Well you could start by saying to him what you just wrote... that you're embarrassed & ashamed & don't even know what to say but that you're going to be seeing someone to begin working through your feelings & yes you'd like to do lunch. I'll bet that would set him back a few paces. You can't undue what has already happened. "Start from where you are" as the Buddhist nun Pema Chodron would say. And as for the "friends" question, personally, I would say don't worry about it. Just deal with what's in front of you now & let the future take care of itself, or as my mother would have told me: "don't borrow trouble." Good luck to you Viuam!