The First Time.

My Bf and I have been together for two years. We keep trying to do it but fail because I'm sensitive down there. It dosent help that the medication I take for anxiety also lowers my libido. He's on the bigger side as well. We are both on the spectrum so that could possibly be a factor. I'm also nervous of the pain and possible tearing. The thing is telling someone with anxeity to relax is like telling one with depression to cheer up plus the only numming creams I see for Anal. also I'm able to get tampons in but they always feel better when I take them out. What can we do?