Pregnancy Depression

I know ppd is pretty common, but I've become increasingly depressed throughout this entire pregnancy. I never remember feeling this horrible with my first baby and just feel so guilty. I see so many moms-to-be posting happy news about their upcoming babies and feel so jealous. Don't get me wrong, I love this baby. But I wish I could feel as excited about my pregnancy, too. It kills me that I don't, and every time I look at my son I just want to cry because he's so ready to be a big brother and I just can't keep my shit together emotionally.

Has anyone had pregnancy depression vs ppd?

Will my chances of ppd increase?

Did anti-depressants/anxiety medication help?

Can you breastfeed while taking the medication?

How do you get over the guilt you feel for being depressed when you should be happy?

I never expected this to happen, and I'm just kind of lost on what to do.