This sucks

I recently lost my virginity to a guy and found out he had been messing around with several other girls, even spending Christmas Day with one of them who I'm assuming is his girlfriend. When I confronted him about it he tried to say she was an old friend crashing at his place, even though I know she's local and now some of his actions (like having to be quiet when we fooled around because he didn't want his roomates to know what we were doing) back up the behaviors of someone cheating. We've gone from talking almost everyday to no contact and it sucks. I have so much anxiety, I feel so tired mentally and physically, and I have no appetite. Some people have said that it's normal to feel like this, since he was my first time but I don't feel like it is. Does anyone have any advice or perspective to offer?