Single and pregnant

Hi I’m a single 35 yr old woman with 2 children 9 and 7 and now currently 5+5 weeks pregnant … I wasn’t planning on having another child… protection was used but I’m highly fertile all the women in my family are .. but my concern is I struggle with mental health issues, I have all my life I’m really unsure what to do .. whether I can mentally handle another little human.. I’ve never ever been one to even think about ending a pregnancy but I’m truly worried I won’t be able to be the best mother I can as I struggle mentally already .. my mum helps a lot with my current 2 children, I’m scared to tell anyone that I’m pregnant this baby’s father doesn’t want me to have the baby because he doesn’t want another child and we aren’t together .. I’m truly scared that I’m going to have to end up terminating this pregnancy which is something I have always believed I could never do .. but realistically what would you all do if in my shoes .. Thankyou x