i just want to cry can someone give me advice

i think my boyfriend has a low morphology or dna fragmentation not sure😔😔 . me and my boyfriend been together 5 years . we tried after being together a year and a half. and in those that year and a half i had 2 chemical pregnancies. then we ended up splitting up , i had sex with this dude (a one night stand) once and got pregnant and had my daughter. after she was born we got back together. and when she turned 1 decided to start trying again in September. i fell pregnant in December had a miscarriage at 9 weeks in February. then been trying since then fell pregnant again this month and it ended in another chemical pregnancy. also his previous girlfriend had two miscarriages for him. i definitely think it has something to do with his sperm any advice? i’m also Rh - and his Rh. + if that has anything to do with it i just need some answers