I have aboyfriend i fell like i have no idea how he feels about me. What should i do?

Hes all into me when im with him. ( alone and with friends around) but when where apart he doesn't text me or call. I feel like if i never called he would never text or call me. But the thing is he says he realy likes me plus he dumped another girl just to go out with me! Also one time i asked to spend the day with him at the zoo. And hes anwcer was "i have friends". So i guess his friends are more important than me. I feel used and he only wants me when he fells like it. What should i do?