by seeing her, after about 3 years since you separated from your wife, pregnant by her lover for the second time with a huge belly?
Which feelings even you know that your marriage is over?
Seriously, dude, grieving isn't just about death, and it's a long (some people would say life-long) process. You don't just move on, but you do have to accept that it is what it is and do your best to come to peace with it.