I have a son whose life sounds almost exactly like yours. Be sure you explain to your friends that if you don't show up to events they invite you to, it isn't because you don't like them. Make the effort to call and keep up communications with them. They will not understand unless you help them understand, and they won't know really what to do or will be afraid of doing the wrong thing.
Just to throw in my two cents: Dealing with friends when you feel rotten all of the time is very hard. It's definitely true that you should try to explain things to those close to you but I'm sure that you feel somewhat uncomfortable spending the limited time you have with your friends talking about
how bad your life is (at least that's how it feels, even if you're just trying to promote understanding). The fact is that some of your friends will have a difficult time dealing with your problems. It sounds a little backwards but sometimes the people who care most for you have the hardest time seeing you in pain because they want to be able to help and feel powerless and conflicted not being able to. Also many people just don't know how to act toward someone who is in pain all of the time. Should they act normally or should they try to console you (and if so, how much?)? Bottom line is that you should keep in touch when you can and know that your good friends will be waiting for you when you're ready to reengage socially. Knowing that people care for you can be one of the strongest motivating factors in fighting to regain control of your life.
DX: NDPH, Recovered CRPS
RX: Lamictal, Concerta (Methylphenidate), Clonazepam, Wellbutrin XL, Namenda, Oxycontin, Oxycodone, Melatonin, Magnesium supplements.
PRN: Ketamine nasal spray
, Celebrex, Migranal, Haloperidol, Zyprexa, Lodine, Zofran, Phenergan, Thorazine, DHE IM, Droperidol IM, Toradol, Reglan, Ambien CR, Provigil, and all triptans