Hi, Bubbaryn, and welcome! I'm glad you decided to join our family. Yes, we do have wonderful members that love to help one another and, as a bonus, we really do care about each other, too. I think you will like it here.
I had to look up "cubital tunnel" because I had never heard of it but guess what? I've had it! 
I came down with fibro while watching television! My toes started hurting, then my ankles, then knees...all the way up my body on both sides. When it hit my elbows, it was like I banged the "funny bone" (ulna nerve) and I got that horrible pain down my arms and into my hands and it stayed that way for over two weeks. I couldn't eat, sleep, and wondered if I was going to have to have my arms amputated to get rid of that unbearable pain! (Your mind does some mighty weird thinking when you are in a lot of pain.) So, I do know what you have gone though and it isn't fun.
When I went to my doctor about this, he put me on high doses of aspirin and then switched to ibuprofen because my ears were ringing so badly from the aspirin. It took months for the nerve to settle down and I had terrible weakness in my arms and hands because of it. This has gone away for me now. It just took time for me.
I see a board certified Internist for my fibro...all of my problems. I, too, am diabetic and I also have Crohn's disease and am legally deaf among other things! But, I've had a great life in spite of all of this and you will too. You just need to find what will help you control your pain and how to work around fibro. If you are overweight, it will help you quite a bit to lose weight. I lost 85 pounds about five years ago and it not only helped with my diabetes but it also helped with fibro. My muscles, tendons, and ligaments didn't have to carry around all of that weight. Also, it is important to keep moving with fibro. If you sit or lay too much, you will be stiff as a board. I see you are finding that out! Gentle stretching exercises and gentle exercises do help with fibro. I walk and swim for my exercise and I do at least one of these every day. It does help with the pain and fatigue of fibro! So, keep on truckin'!
I'm sensitive to medications, too. I take ibuprofen with food (600 mg every six hours), extra strength Tylenol as needed but I never exceed the recommended allowance which is 4,000 mg a day, I take malic acid/magnesium supplements, and vitamin D3 supplements to help with my pain and fatigue. Many with fibro are deficient in these vitamins and nutrients and that can cause more pain and fatigue.
Be sure to check out Fibro 101...the first thread on the forum. There are links to good information about fibro and you will learn a lot. There are links about vitamin D3 and the malic acid/magnesium supplements that I take and also explain how they work in your body. Always talk to your doctor first before taking anything new. I did about the malic acid and he said they wouldn't hurt me so I gave it a try and they really did help! He did a blood test to check for my vitamin D and it was in the dumper so now I take 5,500 IU of D3 a day.
I do think that once you get the pain under control and get moving, your muscles will cooperate more. You can do a sedentary job but you need to get up every once in a while to get coffee or use the restroom. 
Plus, there are some gentle stretching exercises on Fibro 101 that are done sitting down! These were developed for long flights but they work great for fibro. You can be moving without anyone know it! 
You do have a good future ahead of you. I've had fibro for 23 years and have done sooo many things. I just don't let fibro control me. I'm the boss of my body...not fibro! You will find help for your pain and you will find ways of working around fibro to do what you want to do. We can help in that department, too. Many of us have tricks up our sleeves as to how to do things with greater ease. So, put on a smile. Face each new day with anticipation. You could have a great day because fibro waxes and wanes. So, look forward to a good day. If it turns out to be a lousy one, well, you can easily handle that...even with one hand tied behind your back! You are a strong person and have a lot of life to live and to enjoy.
I'm looking forward to getting to know you better. Don't hesitate to ask questions because we are here to help you. I hope to hear more from you soon.
Sherrine