my ex boyfriend..

Kind of long so I apologize.. So history on my ex, we dated 3 years.. we spent EVERY single night together since the day we met. I thought he was the sweetest and perfect. He was so loyal to me. NEVER had girls in his phone. He was dedicated to me. Made me feel so loved!!  Except the last few months of our relationship got strange. He had these "group projects" he had to do for one of his college courses and would be "working" on it until 4am sometimes and then come home. At first I had no reason what so ever to suspect anything. I thought it was weird that they would all work that late but he had honestly never gave me any reason not to believe him. Then he started hiding his phone but I never went through it before because I never had a reason or suspicion to, I just noticed that he would always keep it on him instead of leaving it laying somewhere like before. Than one night he said that he was going to shower and then he'd be over. Well he never showed. And I didn't hear from him until the next morning through text. I was up all night couldn't sleep because I thought something had happened to him. But I had just never seen him after that. He said that he would be over but he never showed he just disappeared and I never saw him again after that. And now six months later, I get my hair done by his sisters best friend regularly and his sisters best friend told me that his family found out that he had met another girl before he left me. And now I'm putting things together that's why he would be out late into the night working on some project I had never even seen when we did school work together and then on the nights when he just wouldn't come home at all. I know I am over him but it all just kind of opens the wound all over again. It hurts because I thought he was one person but then he turns out to be another. After we broke up I had also gotten tested for STDs and I was positive for chlamydia. I had no idea where it came from because I thought my ex-boyfriend was loyal to me the whole time but I guess that just proves the whole point that he was cheating on me. It pisses me off because he met this girl at his work because she was a new employee and I had absolutely no idea. I've just been thinking about it a lot. I want to text him and ask him why. Ask him why he couldn't have just been honest with me. I have a new BF now that I like very much but I just can't seem to not think about how my ex had another girl the whole time. I'm not asking for advice, just somewhere to vent because I don't know who to talk to or vent to about this. It just makes me sick to my stomach that he gave me an STD, that he would sleep with her and then sleep with me and give me diseases. What bothers me most is that I thought he was perfect, I saw him ask a completely different person than what I know now! Sorry girls just really needed to get these feelings off my chest. I feel sick to my stomach 😔😢