When Old feelings and old flames resurface?????

So I have a boyfriend of 8 months . ? He's trust worthy he's honest funny cute laid back easy to talk to etc.. I love him ?.. Okay so before him was my ex . my ex was a liar a cheat etc but he made me feel amazing he always told me he loved me he would always make my heart race he would fight guys for looking at me . he called me beautiful every single day .!!! But he also made me cry a lot .. But the reason I'm telling ya this is because he resurfaced and so have these feelings and I can't help it but think about him constantly and try and find his number and miss em and idk what's wrong with me cause I have a good man . but no body can ever make me feel and touch me like my ex did help please !!! What to do ?!???????