LOST.

It is nice if you have parents or friends that you can talk to about your feelings. But that is a rare thing. Mostly they are very uncomfortable about it, and don't know what to say anyway.
Go to your GP or PCP doc, let them do a physical and blood tests to make sure its not something else easy to fix. Will probably give you antidepressants. This should help. And ask them where you could go for adolescent depression counseling.
Do you go to school? The counseling office there may be able to refer you somewhere for therapy.

You need a professional to talk to, someone who doesn't say stupid things to you when you've gone to the painful trouble of trying to explain yourself. Someone who knows what to say to help you resolve your heartache, and comfort you.

If the meds don't work by the end of the 1st month, go back and tell the doc. The dose will probably need to be increased, or the med changed. If the cost of the med is a problem, there are many "old" antidepressants that are on the cheap. I picked up one last night, Trazadone, it was $4. Explain that to the doctor before he writes out the rx. The old ones are very effective, the drug companies come up with new ones in an attempt to create less side effects, but they don't work any better, and there are still side effects.
It may take time to find the "right" med for you. But don't lose heart.

Do everything you can for yourself as far as try not to isolate in your room, keep doing things like sports, running, walking if you can, make sure you are eating, even something small like cheese, milk, lunch meat. And avoid caffeine and sugar, and of course alcohol and drugs which are depressants. Try and go to bed at the same time every night, and wake up the same time in the am. Train yourself.

As far as your boyfriend, try and be yourself without discussing your depression. He's not comfortable with that, and doesn't know what to say. Some people say "fake it till you make it" and if you can, thats good. Same with your folks. Should they say, well, see you're feeling better, you can answer honestly and say, no not really just know you don't want to hear it. This way they are advised of your continuing situation, but are let off the hook.

Depression is exhausting, so is "faking it". Establish a good sleep schedule. If you don't want to go out, or do something in particular you can always make other excuses, tired, PMS, cramps. Just don't completely isolate.

Please get some help. You have your whole life ahead of you, and it is a glorious one. T

he first bout I had was when I was 19. Hubby was in the army and we were stationed in Germany, I was alone all day with no money or friends. W ent to an army doc who gave me Tofranil, an oldie, and I somehow wheedled a job doing dishes at the snack bar. Had to walk to the bus, and started speed walking because I was always afraid of missing the bus. I recall telling the doc that I had never felt so happy in my life. There was a pop song then, adopted by McDonalds, "Feeling Groovy", used to hear it in my head, ha ha.
We didn't have therapy in those days, which would have helped because while I was alone, my family's problems ate away at me. Someone should have told me I don't have to solve them, and that it was selfish and unfair of my parents to dump their crap all over us.

This is the perfect time for you to get going with the family doctor, as schedules get tight around the holiday and people in general are trying to squeeze in before the end of the year, and it is a time of year that is stressful and depressing for many.

Hope you will get the ball rolling.
You are not alone, this is a great place for venting, and support.
Thinking of you ....