How do I progress in a new relationship when I am still haunted by my past relationship?

Do NOT let him guilt you into going back. My ex guilted me back, and before long, I was unhappy again so I left again, so he guilted me back and before long...it went on like that for 3 years. It was miserable! Yes, I loved him and I wanted him to be happy but I was sacrificing my OWN happiness for his. I finally made a break and moved 2 hours away just to be free of him. Probably the hardest thing I ever did, and yes, he called and cried and said all I ever wanted to hear, but I stood my ground. 5 years down the road, I'm deliriously happy with my new husband, our home we just bought, our 2 year old son and my own business. Sadly, I get the random email from my ex, one even proposing we get married and try AGAIN, and he knows my situation. I ignore them and today, I got an email from him with pictures of his new gf, telling me how amazing his sex life is now. I know he's trying to hurt me, and it works on some level, but then I look at my husband and our son and remember how happy I am. I am sorry that my ex can't find happiness, but ultimately, thats his problem. Follow your happiness and I wish you the best of luck.