Please help, what should I do?

Me and my ex have starting talking again after realising things, and we are just seeing how things work out. As he was my bestfriend prior to dating, so we are friends at the moment but it's more than friends.. but we aren't dating as it's not the right time and we just want to get to know one another again, and it's not something he can commit to and I don't want to get hurt. I'm trying so hard with him and to show him I've changed but it's a little frustrating as sometimes he ignores me for long periods of time or doesn't respond, it seems I mostly initiate contact. I'm not expecting him to talk to me 24/7, I understand he is busy and has his own life. He willing talks to me all day, but sometimes mostly on the weekends his communication gets real poorly or when he's hanging out with his friends, but it would be nice for him to say I'm busy talk later rather than ignore me, I find it rude and if I bring that up with him, I get a lecture on how I'm being crazy psycho and that I'm still immature etc. I'm not trying to act that way but it makes me feel as if he doesn't care. Sometimes he acts strange but whenever we talk over the phone he's so happy and tells me amazing things, he's not one to open up or talk about his emotions which can be difficult but recently he has been more honest and we are making progress, but it's like one day he's good then one day he isn't. I have been making a lot of effort and chasing him entirely, and I do everything to show him how much he means to me, I just feel it's not reciprocated and that I'll end up hurt. But it's things like this that make me worried and I don't know what to do. We had a little disagreement two days ago and he hasn't responded to me at all so I waited but he didn't text so I text him saying hey, but he ignored that too and I still haven't heard from him...
I don't want to argue with him if he texts back but it's not okay to do that. Should I back off? and how to do so?
Please help, what should I do?
Add Opinion