I let a guy make me feel worthless, I don't know how to make this feeling go away

I stupidly let my ex back into my life. He hurt me once before but it's been years so I gave him the benefit of the doubt when he said he changed. We talked again, a little flirting but mostly catching up in a friendly way. We talked every day for about a month and he disappeared pretty much. I asked him if we are still trying to be friends and he said of course and we talked again for like a day and low and behold, he disappeared again. I feel really stupid for letting this hurt me. I can't help it though. He came to me and seemed so interested in talking to me again, sayin he always thought about me over the years. Idk what I expected but I'm hurt. I feel worthless. I feel not good enough. I feel like he thinks of me as disposable. If I would've known this would've effected me I wouldn't have answered him. I thought since its been years I'd be cool with whatever happened. Anyway, I need help. Please. How can I regain the feeling of worth? How can I feel good about myself again? Thank you.