One of my brothers friends admitted to me that he had feelings for, but was in a relationship with someone else. I had told him that nothing could happen while he was with someone else. We however became close friends for 3 years, hanging out with each other, playing cricket etc a lot of things happened in those 3 years, his girlfriend found out that he had feelings for me and " hit the fan",we never talked for over a year, and then I found out that he left his girlfriend and moved in with my brother. Anyway the day of my brothers birthday we went to the show, this guy presented me with a gold necklace (he told me it was to say sorry for all the hurt he had put me through in the last few years) we started dating and were together for over a year, for my birthday he presented me with a diamond engagement ring, recently we had a massive fight and stopped talking, he has met someone else since, I don't know if its official as he is still txting me saying that he cares for me and loves me. He has always told me that I'm the only girl he has truly loved as he had never thought about settling down with anyone until he met me. This I know as a fact.
I honestly believe that we have been through so much together and we keep finding our way back to each other
Do you think I am wasting my time believing this is true. I told him the other day that I was thinking of moving on, because I didn't know whether he wanted to be with me, because I didn't want to be hurt, although he's the only one I want. And he went all funny at me, as if he didn't want me to. Does anybody think that there is a slight chance here?

Sounds like a cheater to me. He constantly has feelings for other women while in a relationship. Though simple having feelings for someone else while in a relationship isn't fatal, it's fatal when he acts on those feelings. He told you that he liked you while he had a girlfriend. That was a huge red flag already.

Apparently he wanted to marry you one day, but a little while later he's already talking or with another girl. Another huge red flag. It sounds like he was never really committed to his relationship with you.

Such an insecure relationship is extremely unheathy. Who knows when he'll start liking another women and act on it as well. Ride yourself of all this heartache and end any association you have with this person.