Jealousy

I get jealous of how happy my ex and his babymama act they live together now with their lil family and it still bothers me so how to the point where I wanna take him back because that was suppose to be us I just wonder if I didn’t lose our daughter we could’ve been that happy family now I’m alone 💔 is this even a thing I should be jealous about I can’t help it we still talk we even planning/trying for another baby together but I don’t want me and my child to feel like we coming last maybe it’s time to let go and close this chapter and find somebody I don’t have to share but it’s hard walking around when I love him so much