@Fuzzyhippo wishing you the absolute best for this pregnancy.
Living apart can work, but make sure you have confidence in yourself.
For the birth, are you living with relatives that you would feel comfortable accompanying you to the hospital and waiting with you if there was a wait to get hold of your partner ? If they would not be able to accompany you, ( e.g there own health etc, or you would just rather they didn't !) then please don't worry about heading in alone. Go to the maternity unit when medically advised, ( by taxi), do not wait around for your partner if he takes a while to respond. My friend had to give birth alone twice, ( childcare reasons, her and her partner are from abroad and she wanted him to stay with her SEN DC), and she said the midwives couldn't have been more brilliant with her.
Hopefully this is irrelevant and you will be able to get hold of him quickly, but just wanted to reassure you will be looked after well if for any reason you have to attend alone.
I also remember seeing your other thread about the horrific trouble you had getting a scan. Have you been referred/ seen by NHS Midwifery / scan now ?
Also, if you didn't want to attend hospital alone, would home birth be an option you'd consider ? ( The NHS would send two midwives out to your home). Wishing you all the best.