Heart Skipping a beat, driving me NUTS!

Bare with me folks I have a long story maybe you can help me out .

Hello People of the forum I decided to sign up to get some advice or maybe hear a story about a similar issue some of you might be dealing with.
I'm 26 years old I have a sedentiary office job. I'm Overweight but since i turned 18 I started to do a lot of sports(Football and Basketball) and gym ( mostly cardio for endurance for sports )I like to drive myself very very hard and have my heart literally pounding.. been doing this for years tho and i never had a problem. I never used to watch what i eat so i eat quite a lot of junk so I never really lost that much weight (10-15 pounds in a year maybe. am eating a lot less lately and a lot less junk ) however since january I have had this wierd feeling in my chest and i thought its probably a stomach bug.. then i noticed it more and more specially before sleeping and i checked my pulse and i was skipping a beat every 5 or 6 beats or so .. then goes back to normal for a few 20-30 or so beats then restarts like a cycle.
Its never continous . it comes and goes.sometimes I start worrying about it and start feeling my pulse again and it skips even more often.
Theres no pain but a slight thump in my chest. It makes me a bit dizzy sometimes.

I went to the doctor.. he listened to my heart and he said he didnt hear anything abnormal.. the skipping of the beat is something all people have once in a while but never really notice it.. he said most probably it is a lot to do about stress/anxiety at the workplace or at home or both. now a lot of people consider my job stressfull ( call center sales etc.BTW im NOT a telemarketer i work for a bank in the UK). I never minded it.. sitting down and talking to someone on the phone never seemed something stressfull to me.. yes we have targets etc. but theyre easily achievable to me. my job is safe been working for the same company for 5+ years i dont have any worries about that. My only recent worry is my mother as she had to go through a knee operation and she is finding it extremely difficult to cope with it ( she had the op 2 weeks ago.. we knew she was gonna need it for months tho so it was all planned. I moved in while shes getting better for assistance too).

The only thing that keeps lingering maybe is over a relationship that ended very sour and im very hung up about it.. yet this has happened 6+months ago sand i never had my heart skip a beat until january.

Today i had a very heavy basketball session. 4 games in three hours end to end stuff and ran a crapload. Usually when i exercise the Heart doesnt skip so often in fact it relieves it but today its skipping like mad.. in fact im a bit dizzy right now. but again . no pain.. just that thump..

should I worry ? I already went to the doctor but i feel like he kinda brushed it off as anxiety. he gave me these natural light sedatives ( sedivitax bio) to take before going to bed. it seemed to help a bit but i still have these skipped beats sometimes. I dont wanna keep taking drugs for the rest of my life.

My apologies for the long post I appreciate your patience in reading all this

Hi Walrus

First of all, I'm not a doctor or specialist, so don't regard my post as absolute gospel, always get your symptoms checked out by your GP or Healthcare Advisor. What I say below is only from my personal experience of these palpitations over the last few months and nothing more. It sounds to me like PVC's or PAC's (Premature Atrial or Ventricle Contractions) that I experience on a daily basis. Been happening since December 2012 and have been to A&E too many times to mention. These A&E trips were mostly at the initial stage of the onset of the palpitations due to lack of knowing what they were. I kept thinking it was something really really serious, which to an extent it is, but not life threatening. After many GP visits and a visit to a cardiologist, I have been excluded from any heart disease and assured that the palpitations are benign. Have had bloods done, treadmill stress test, tilt table test and echocardiogram. All come back clear or fine except the tilt table test. They used the tilt table to induce a "panic attack" which they concluded was the reason I was having my palpitations. They said it was stress/anxiety related and I needed to address issues before it would get better. So three to four months later I am still having them daily. Sometimes when I walk, sometimes when I get out a shower/bath, most times through the day for no reason and each night when I'm laying in bed trying to get some sleep. I haven't been able to pinpoint anything that makes them better or worse at this point, so can't say I'm a great help in that sense. What I will say though is that I have tried to understand the anxiety that is supposedly responsible for the symptoms and it baffles me somewhat. I can't pinpoint what my stressors or aggressors are to bring on the anxiety either but I know for sure that the palpitations cause a great deal of the anxiousness I experience. Makes me think of the "chicken and egg" scenario, not sure which came first when I think about it, the palpitations or the anxiety? I feel the thud you mention but also feel what I guess is like a tickle. Both these make me feel a bit dizzy, but it's like instantly there and then gone again, the dizziness doesn't linger. Apparently the thud or tickle depends on where the additional beat happens to come in during the "normal beats" and the thud is due to the heart having a lot more blood in it to pump out while the tickle is when it has very little from what I understand. Apparently this is "all normal" in a structurally normal heart, but each and every time it happens, it still scares the life out of me.
I would suggest you visit your GP for a referral to a cardiologist so that any structural abnormalities can be ruled out. In majority of cases from what I've read or been told, once that has been ruled out, your palpitations will most likely be "benign" and "nothing to worry about" which is seriously easier said than believed. The reality is anything related to the heart scares us and that's why most of us are here, for reassurance and help in dealing with them.
I wish you well in finding an answer and remember to post anything you find that helps or aggravates them, it could be useful to some people. I read on one post that if you are exercising to the extent you are, you could possibly have a low iron level which could cause them, but seeing your GP and having bloods done might tell you if this is the case. Always best to get advice from the GP or from a specialist.
Take care and hope to hear something positive soon

Cheers