Attached

Hey ladies so I am a wreck. My partner and I are in a difficult relationship. Because of past situations I am always anxious and worried about him and just the things he does, I can't do that but I am and it's draining me. I want the best for him and I love him with all my heart but I'm not sure what to do. If it takes him more than 20 minutes to respond I get anxious, I don't like that I do but that's what's happening. He is completely fine with going off and not talking to me for a long time and I get anxious over 20 minutes, and I need help to not be so attached and not so involved because I'm afraid I'll scare him away and I just want to be fine on my own. I don't like that I've become dependent on him and I need help to change that. Help please