Indie... you are most definitely not a slut and I hope you aren't going to continue beating yourself up over this. Other than the technological aspect this is really pretty normal behavior. Of course that technological part adds a lot of complications to an otherwise normal event. I'm not familiar with video chatting but I am aware that vid chats can be recorded. Other than the possibility that he recorded and shares the vid with friends, nothing terrible happened here. I understand that you are regretting this and feeling shame and embarrassment. I'm so sorry for that. It does not change who you are. It's something that happened in your life.... not something that defines you or your character.
Like others have said, this is part of growing up. Despite religious and moral posturings and all that, we are all human and we are all sexual. Both those came into play here. What happens now I obviously don't know. It sounds like there was a lot of genuine personal interest on both sides so it probably will stay between you and him.
I think you should bring it up with your therapist. I hope she/he can help you put this into perspective. You're still the same Indie to me.