Sex with a cronic illness

So I have ulcerative colitis and psoriatic arthritis and I have been stiff, swollen, and hurting for quite some time. Lately I haven't been able to have sex with my husband because of it. It's not that he doesn't want to have sex with mw it's thay he's afraid he will hurt me more than I'm already hurt. I completely understand what he means and where he's coming from. It's just the emotional side of me says I'm only 23 why should I have to deal with these problems at this age. Anyone have any positive vibes???