I was born in 1975 Rabbit year . I need your advise on my relationship

My partner was born in Monkey year. We been together for more than 10years but last month, he told me he fell in love with someone else (born in Dragon year). Now, he said he had forgotten about her and is trying to patch up our relationship. Even though our relationship appear fine and better than before, i have a gut feeling he is not entirely happy (even though he tries hard to show he is). I suspect that he is still waiting for her to accept his love (he still sees her at work), i did question him several times but his answer is always not the case. Do I stand a chance with him? I am doing my best to win him back but it hurts sometimes that he feels sad or discontent. When i asked him why he isn't happy, he will come up with numerous other reasons, which i find not convincing.. Is there any advice for me? Please help.