I have a friend, we have known each other for about a year... We both were under the impression the other was straight but we got closer over time and recently opened up to each other that we both had feelings for each other.
I am in a m/f relationship, she is very open with me exploring my curiosity. I had fooled around a few time as a younger teenager but never got to open up or explore. He has never had sex or fooled around with a guy or girl....
Very quickly "one day" turned into "lets meet up tomorrow"....we discussed the things we wanted to do and said we'd take it slow.

I went to pick him up and we went to my house and started watching star-wars. He went to the bathroom and came out in his white briefs. Things got going really fast after that. We fooled around for over an hour. It wasn't awkward or anything during, in fact it was really enjoyable. After, we layed there finishing our movie, had dinner and eventually put our clothes on and I took him home.
It got weird when he got out of the car and didn't give me a hug..hes hugged me every time ive seen him since before we actually got to know each-other. I figured not to look into much because we both had feelings to figure out and what not.
It's been about a week since then and we barely talk (we sent 100's of texts sometimes a day). One night he texted me in the middle of the night and said something along the lines of "I enjoyed it a lot, id like to do it again but I moved too fast and I want to get comfortable around each-other again."

I replied saying I understood and felt the same way. Let's take our time and see what happens, no pressure. Let's always be friends (something we had discussed previously to fooling around).

I'd like your advice on how to help him get more comfortable and keep him as a friend. I looooved fooling around with him but losing him as a friend isn't worth it. I'm afraid though it may be too late.

It does sound like the reality of what he did is may be playing mind games on him.  This is a guy who lost his virginity to his male friend….it may be a lot for him to process.  In the moment when guys are horny it’s all good…he may be second guessing himself now that it’s happened.  I would think the best thing to do is sit down with him and have a talk.  What did he think of what happened?  Did it feel weird?  Did he expect it to be different?  Does he still have feelings for you?  What makes him feel uncomfortable to be around you now?  Have it all out with him with the agreement that afterwards you put it behind you and either go forward or move on as just friends.  The whole ‘if we don’t talk about it it will all go back to normal’ is not the best approach.  Assure him your friendship comes first and the rest is just icing on the cake but either way it’s okay.  Hope that helps hon…good luck! :) xoxoxo