He tells you that he loves another woman and doesn't love you yet you still want to be with him. Does it not upset you? You deserve a guy who loves you, not other women. You would benefit from working on your self esteem so you don't go for unavailable guys. You are young and can meet nice single guys in the future.

I also recommend to take things slow. Last guy you only dated for few weeks and already wanted him to propose. It's better to date a bit longer before having sex and going on long vacations or thinking commitment. This guy is full of red flags and IMHO you can do much better than him