Are you able to put her in nursery? Or ask for support from family?
Give yourself a break from LO and go for a walk and coffee on your own. As hard as it might seem. You need it and she will also learn that you are going to come back, and anyone looking after her will just have to deal with it and find ways to distract her and keep her happy. It can't and shouldn't all be on you (single parent here, so I know all this is easier said than done)
Feeling this atm too, I'm 31 weeks pregnant too and sick at the moment so I'm like pleaseee just go to someone else for a bit 😵💫, stop climbing all over me and being clingy. I'm sure it's just a phase though, in a few weeks he will probs be back to wanting his dad all the time 😅