Rheumatoid Arthritis Treatment

Sorry if this gets lengthy. Feel free to scroll to the end — the real questions are there. Thank you.
Those of you who know me from R&S are aware that I have rheumatoid arthritis. I’ve been in a blue funk, assumed it was my disease, and sought the help of a therapist. She recommended I speak with the clinic’s psychiatrist, and the diagnosis, when it came back, completely floored me. Me, diagnosed with a mental illness? Impossible. Or so it seemed.
I’ve spent several days learning about this disease, and in doing so, saw my life with a new clarity. The violent outbursts as a youth, running away, quitting school, going through jobs, getting fired repeatedly, alcohol and drug abuse, a suicide attempt … it all fit.
Oh, how I wished my parents would have sought help for me when they saw there was a problem rather than issuing beatings. My life (and the lives of my children) could have turned out so differently. I suspect my mother is also bipolar, and I suppose my father had enough to deal with. Knowing this does bring some closure to a very traumatic childhood.
With age I seem to have mellowed a bit — the manic stages being less dramatic but the depression worsening with each cycling. Still, I find myself irritable and snappish, frequently tearful, always guilty … These are things I will discuss and work on with my therapist, but she’s on vacation and I don’t see her again until the thirty-first. I’m seeking answers now.
For those of you with bipolar or another mental illness, advice, please. While I absolutely respect my therapist, it is you who lives with mental illness. How do you cope?
What do I tell my kids?
Can I learn to control my snappish moods, or does this come about through the use of meds? What coping skills do you employ?
How did you get over the stigma of having a mental illness?
I frequently misunderstand what others mean when they speak, cannot catch sarcasm, have no humor and take things personally — How to get around this?
I have no friends, yet I am frequently lonely. I will do all I can to push others away from me, and will deliberately do something to make them turn from me. I would like to be surrounded by others, but I have rushing thoughts and rapid speech. It’s humiliating, and I hate it. If you have gone through something similar, how did you get over it? CAN you get over the rapid speech? If not, then how do you learn to live with it? These speech patterns are present even during my depressive episode — it never goes away.
If you were diagnosed later in life, as I have been — how did your life change after starting medication? DID your life change? Does it ever get any better or do the moods just level off?
My apologies for so many questions. Please, pick only one and answer it. I don’t expect anyone to answer all of them, but if you could just lend some insight and useful advice, I’d appreciate it. Thank you for your time. All sincere answers appreciated.