LAT relation with my ex-husband and in love with another

Hello

I am a mother of two young children (5 and 10).
I am divorced, after a year we kind of came back together again, now we have a LAT relationship.

But not so long ago I fell in love with a fantastic guy with whom I find much more fun and understanding. My ex-husband is manic-depressed and quite selfish.

He is also not so good with the children. The eldest has a development backlog and that often clashes. He calls her names and is physically rough, also with my youngest daughter.

Still they love him naturally it is their father and they want to be with him, I don't want to take that from them because every child deserves a father and mother that are together. That is soooo much in my mind.

My ex-husband can also not be alone with the children because of his disease and he has no authority over the kids and he gives in to keep them quiet, so I am always there one time at my place and in the weekends at his place.

But when I continue with this new guy something will have to change and that scares me so much. Also to not see the children in the weekend, I miss them soooo much then!

My exhusband already gets support from a family coach but he doesn't listen to her, thinks he knows it all better himself.

HELP!!! WHAT SHOULD I DO????????