How to solve probs. in a relationship ?

I'm with this guy for more than a year now , and recently we've been fighting a lot for example , i'm not honest and straightforward towards him its because i'm afraid wat if wat i said to hym will make him angry , he find it hard to trust me after wat i did to him like lying to him , contact my ex , i hurt him a lot . i tend to feel jealous easily wen girls contact him , whenever i feel sad or jealous , i always let out my feelings towards him but he doesnt even let out of how he feel n ended up idk wheather his mad or sad and wen everytime we fight his always the one who say its over but somehow i feel i'm also at fault of fighting with hym.And his telling me dat his mind was saying to change his attitude n find a new girl.I just want to fix this relationship , i want to gain the trust back..any advice ?