You're dealing with a lot. Your pregnancy, Gestational Diabetes, your H's affair, your dad's potential cancer. That must be incredibly difficult. Try to take some time to step back and breath. You will get through this.
It's great you're making an effort to get together with friends. Their support and the relief of dwelling on everything else will help you quite a bit.
I also agree you don't owe H an explanation of where you'll be or what you'll be doing. He's given up that right due to his actions.
Me:39 Ex-W:37 M:7 T: 9 S:6 D:3 BD/IHS/Confirm EA/PA: Feb '20 OM1 affair ends: May '20 W/OM2 & moves out: June-July '20 W files for D: Jul20 OM2 confirmed: 9/2020 Divorced: May '21