He knows he can hurt you and he will do it again. 

If he knows that you will always be there to take him back, he will do and say whatever he wants. He won't be the boy you deserve. You won't be a priority. He will do really really low things and not have to worry about consequences if you are always there to take him back. Make him know that you know you're worth and you don't need to put up with his sh*t.

"He says he misses me but won't act upon it," then he doesn't miss you enough. 

"I miss you but I'm just not in the mental state to be in a relationship."

Then leave me alone.

Make him miss you. Make him want something with you and treat you like the queen you are.

If he wants you and only you, he will show you. 

If he wants you he will prove it to you every day. He will be more than happy to remind you every day how much he cares about you and how lucky he is to have you.

Mature men are not toxic. 

If he is mature he won't treat you bad. He will be everything you've ever wanted. He will be fully aware of your worth. A mature man will never go a day knowing that you're upset (at him or something else) without trying to say or do something to make you feel better. A mature man will love you for all your perfections and imperfections. He will love you for you.