Can't get out of my head...

Sat here absolutely distraught that my bf left me and our kids for another woman whom he also fathered kids with. It's been 6 months and I'm not over it and not moved on at all. I'm still as distraught as I was the day he left. It's really affecting my mental health and I just burst into tears all the time throughout the day and night. It's so exhausting. The heartbreak and hurt gives me physical symptoms too, I get pain in my chest, abdomen, head, heart. I can't breathe at times. I am having therapy but it only makes me feel better for that 1 day, the rest of the time I'm in a mess. They've increased my medication but it doesn't help at all. I can't get out of my head or my feelings. He's living his best life, even expecting another child with this woman and proposed to her, yet here I am absolutely distraught and unable to see a way out. I also have anxiety and find it difficult to leave the house. Along with having no friends, family or support I'm stuck indoors with my heartbreak and hurt going round and round in my head. I don't know what to do to stop my depression spiraling out of control any more than it already has 😭😭😭😭😭😭😭 SOMEONE SAVE ME, I am falling and falling and there's nobody to catch me 😭😭😭😭😭😭😭