We are all human so we make mistakes. Cut yourself some slack and be kind to yourself. Give yourself time to be sick (it is an illness) and time to recover.
I believe that ultimately it's God that needs to forgive, not us or anybody else and he has already done that. So take heart in that.
My life changed forever when I stopped beating myself up over every "mistake". It took a lot of therapy to get to that point but I think that had as much of an effect on my mood as all the meds I take.