Believe me OP, I tried to convince myself that my ex still cared, wanted me, etc. it's because he's a coward that he's treating you this way.
What he should do is man up and say he doesn't want to be with you. What's he has done instead is take a "break" which leaves him free to date/shag if the opportunity arises and he can be guilt free because you aren't together. But he keeps you on the back burner by giving you a little contact, a little hope.
I know you don't want to hear that or believe it. I certainly didn't at the time.
If he cared about you the way you care about him, he'd be more concerned with your feelings and not want to put you through this emotional roller coaster.
Take care of yourself, look after your feelings. And ignore, ignore, ignore. If he wants you, he'll come back and be with you full time.
You shouldn't be in a relationship where one person holds all the cards. You shouldn't live in fear of doing or saying the wrong thing and "messing" it all up. That kind of fear is destructive to you as a person.
My relationship with the ex was all rosy and fine too until problems set in, he wasn't happy with his job, he was stressed. Nothing that had anything to do with us as a couple but there was always an excuse. And I kept buying them until he found someone to replace me with, because I wanted it to work out. He just wanted a warm body until he found someone better.
I'm sure you'll read this and think it's not the same for you and maybe it's not. But you need to really examine your relationship and what's going on and if any of what I've said rings true, then pull away. Take the power back.
I'm rooting for you OP. there is life after such relationships. And it can be so much better