How do i stop being clingy?

I am getting married in 3 weeks and i am soo in love with my fiance' of almost 4 years. now he has been hanging out with an ex that he dated for a month a long time ago. The problem is she wants to be with him. i am not worried he would leave me or cheat on me. i just cant help to feel the way i feel when she constantly texts and calls him asking him to come over and hang out, or talk about how miserable her bf makes her feel. i know she wants to be with him and he has told me that. but he told me that he would never go back. now the problem is i find myself calling and texting constantly like she does, idk why i am doing it maybe to show him i care more idk... i havent been really wanting to leave his side at all and im afraid i am smothering him and i need help stopping this before i drive him away from me. it makes me feel terrible to do this to him even tho he hasnt really said anything about it. please please help :(