Long-term relationship troubles

Basically I've bin with my partner for 15 years we have two children and live together, just wondering if anyone's bin through something similar, I love her so much , but we've had a few problems the last few years due to me drinking and working , she also works alot which take alot of her time up , a few month ago we had a break up for a month or two , in that time she slept with someone I know quite well and Basically i thought I could get over it but it's all I think about and it's broke my heart, like I say I adore this women and she's the mother to my children, I just can't stop thinking about her sleeping with someone eles , is there anyway I can get over it as its affecting our relationship bad , I'm drinking and going out alot wich also is talking it's toll on the relationship, I just can't get over the fact the women I've loved for 15 years has done this , I'm far from perfect at all but I'm just asking if anyone eles has bin through something similar, I love the bones of her but I just can't get it out my head no matter how much I try , is it even possible for me to get over this ?
Thanks guys