I feel weak, lonely, & depressed

My bf and I went on a trip with his family & even though I was surrounded by loving people I felt so lonely. We were engaged but I don’t wear my ring or mention my engagement because he’s a big manipulating, cheating liar it was like I was engaged to myself he never mentioned it to anyone. While I was wearing the ring he text the person he cheated on me with saying he’s not getting Married to anyone. It’s so hard to sit and deal with this feeling I have so many triggers and I want to trust him but when I do I’m let down again. I started therapy and my therapist says I should use being happy around him and not arguing as a strategy because when I build myself enough I will leave when the time is right. Right now I’m not working he is and we have a child together. I don’t have anyone else to turn to and I’m in school. It’s just so hard to not be upset about him cheating, coming home late and stuff I can’t even get 50$ when I ask but when his car gets towed, he would throw $1,000 at it instantly. Doesn’t help take care of our child, he doesn’t clean, no dates nothing it’s hard not

To nag and complain about it all I do is ask and try not to argue but it’s upsetting. Idk how long I can put up with this for. We been together for 5y now.