Hi everyone, I'm Megan and I'm 34. I got married 13 months a

Hi everyone, I'm Megan and I'm 34. I got married 13 months ago (we were together for 9 years). About 4 weeks ago I found out my husband had been/still is having an affair for the past 4 months. I'm not 16 weeks pregnant with our first baby. I'm so mad, hurt, confused, pissed off, I feel like an idiot because I knew something was off for months, but he kept lying and lying. I tried everything to fix our marriage before I knew the truth. It's hard to believe that this man is the same one I was with for so long - did I just not see the real him for so long? Or did he change when he met this other girl? What type of person keeps up an affair with a married man, especially after she finds out his wife is married?
I'm trying to work through these feelings, but it's hard because I own 2 small businesses and can't just take time off to process. My therapist says I'm still in shock. I might be?
Luckily, he did this so quickly after our marriage began so it should make the divorce pretty quick. I have some assets that are pre-marrital and it will all stay with me, I don't think he realizes this. Financially I'll be fine. But I keep thinking what was all the hard work for if I'm alone now? I thought we were working towards the same things.
How am I ever supposed to trust anyone after all this?