How do I stop being so dependent on men?

I just want to be able to be happy with myself and confident that I don’t need anyone. Over the summer I was single and felt happier with myself than I ever had before. It took me a year after a breakup to get to that point. But now I’m seeing someone again and I’ve gone straight back to being clingy, feeling worthless, comparing myself to other people and being totally dependent on him and his attitude towards me. I love being in relationships and I love loving people, but I want to be able to love someone and not completely pin my entire worth on them. Is this ever going to be possible or should I just stay alone all my life?