Hey everyone! I need some advice about my relationship...

It’s been almost 2 years that we are together,the first year everything was great,everytime he was traveling & we talk all day long..when we miss each other I’d fly to see him...when he came back in June we moved together..one day I was lurking through his phone & I found a number that I don’t recognize... I saved the number on my phone & when he left the house I called the number and a girl responded.. I asked her and told her about my relationship & she told me that she’s is waiting for him to come back & get engaged... I was shocked.. I meet the girl & she explained the situation and it turns out that she’s an ex that he wanted to reconnect with just for sex and that she lied because she thought that I was lying.. I forgave him because I loved him... after one month he was drinking beer with his friends at a bar and meet another woman & went to another bar till 5 am (I was asleep) he took her for a car ride and asked her to go somewhere else.. she said no and send her home... I found out again by the number that I found in her phone.. again I called the girl & she said we just drank something he asked me o go somewhere else I said no..I swear he didn’t mention that he has a girlfriend...that’s all... i cried & still forgave him...shit happened again... approximately 2 weeks ago ... I found out that he was in a massage center (apparently they offer not only massage there) & he was seeing someone there,again just for sex! I don’t know what to do.. I love him but I think that he won’t change & the fact that I forgave him makes him think that I’ll forgive him again & again!! (Sorry for the grammar mistakes but I’m not from England 😞)