NEED TO VENT

No sure if this is the right place to vent but I have no one to talk too so here it goes my story I’m 18 years old with a 9 month old baby girl and still together with her father ... he is 21 and has a 5 year old baby girl with another girl , long story short about why they ended stuff ( was bc she was getting laid with another dude ) back to to reason I need to vent We been struggling and stressed and tired of ppl screwing us over and feel like we really need a fresh start somewhere , he told m this

I don’t want too , idk how to make him understand I’m not ready for that without hurting him I know he meanly wants to be there for his baby girl but does it matter how I feel ? Am I being selfish by not wanting to ? Would it even be healthy when my daughter grows up ? Like oh hey mom why you living with dads ex gf ... I love him and all but I just feel like I’m to young and I’m holding him back ... I just really need advice .