I need help!

Hello ladies I need advice!

My boyfriend & I have been dating for a while.. he has a son who’s 3 years old. He’s adorable! He’s everything! He also said he has a 5 year old son which he barely talks about & shows. Well, turns out that he’s not the father of the 5 year old boy. Him & his ex dated for 2 years & broke up.. so he said to me yesterday “if a man raises a woman’s child that’s not his he’s in love with the mother” & I asked him if he knows what he said he said Yes. I asked him 2 more times & he says the same thing that the man is in love with the mother. It made me feel a type of way?? I won’t lie🙁I do have a daughter & a son that he also likes to be with but that made me iffy? I have NO issue of him being involved with his sons brother! Because their brothers!❤️but what made me iffy was him saying he’s in love with his ex.. in the beginning of the relationship he said had feelings for his ex still but then he denied it. So maybe I’m just being crazy?😔but idk .. i have BPD (Borderline Personality Disorder) so I am very sensitive. But in the beginning of the relationship his ex was sick possibly with COVID she wanted him to drive an hour to go see her & take care of her.. ladies I’m a good person I promise I am!! But i feel like a b*tch for feeling this way I am shutting down😞, my boyfriend wants to marry me but I’m not sure I can really accept this rn? Like I don’t understand.. he says his ex was HORRIBLE the relationship was TOXIC & she has a boyfriend who cares for both her childrens but idk i feel a way I’m sorry if I sound like a b*tch🥺it threw me off when he mentioned the love the mother still etc.. ladies and I horrible???😞😞I tried telling him how I feel then he snapped? Like he made me seem like a horrible person but it’s not about the boy’ it’s what he said about the Mom🥺. When he snapped he told me I don’t care for our relationship??