Self confidence tips

No matter how many people tell me I’m pretty I don’t believe it. It’s really taking a toll on my mental health. I won’t get into a relationship and it’s because of me not them. They all think they’re the problem. I just resemble someone who I wish I had no part of. I resemble my mom but I look like my Sperm donor and that side. I hate I cause I hardly know them. He’s someone I don’t want to surround myself with. The fact that I look like him kills me and I don’t like myself because of that. I don’t know what to do.