How can i get over my partner's sexual past ?

First of all, you are not alone ; and you are being too much of something (jealous, controlling...). It is an issue most people will encounter. I would suggest that above all, you ask yourself why you are feeling upset about their sexual past : maybe there is a bigger picture, and a bigger issue, you might need to be looking at and facing. For me personally, I knew where it stemmed from. Once I had put my finger on it, I could move on to something more pragmatic. Think about yourself and your sexual past, does any of it mean anything to you right now? Does it even matter now that you're with your current partner? My guess is : probably not. The answer is very likely to be the same for your partner. You could very well so address it and talk it through, if you are feeling confortable enough!