How do I know my boyfriend really loves me

Well I been with this guy for three years I'm some what engaged to him but I know when we first started dating I found out he was cheating on me and tells me that he thought we weren't gonna last. But now he changed the only thing is he doesn't know how to fix problems the stays saying here we go again why do I always wana start why can't we just be happy together and I tell him what he did then says sorry I notice as well that he lies a lot he hasn't even giving me my engagement ring his mom text me saying he has it but idk I don't even think he saves up on our wedding I freak out and try to save but idk what to do he says he is but I can't believe him because he's lied before n when I tell him he says don't believe me then he says he mite give me the ring on my bday but he wants his mom there I told him I wanted between us I feel like he is never gonna give it to me that  he's just playing games with me n trying  to get into my pants yea he's bought me stuff a lot constantly when he gets paid he spoils me but idk what to think any advise