marie, first of all, a straight question. Do you think you may have MH problems? I appreciate this is a very difficult question for you to know the answer to, but perhaps dealing with your daughters behaviour over the years has caused a deterioration in your MH?
Just wanted to get that out there first.
Could you speak to your ex and your mum, separately, and see what has been said about you, without getting too overwrought?
It may be that she believesyou have MH issues, even if you don't.
Once all of that is learned out of the way, I would suggest you calmly (!) text your daughter every few days, just to say something chatty. Do NOT send her a text every day saying you love her, more grist to her mill, just a 'just back from shopping. New coffee shop open, we will have to meet up there sometime' type of texts. Keep in touch with ex and mum, not only asking for info about daughter, but just to let them see you are okay.
Finally, and I say this with the best will in the world, see your GP. Could there be a possibility that you are suffering from depression? Even if you go and GP says you are fine, it is 'logged'.
Be kind to yourself and stay in touch with everyone, no matter how hard.