It will get easier with time. You need to look after yourself now, try not to let anything your H does get to you.
My W used to know exactly what buttons to push over the last 9 months, but those buttons are U/S now.
It's good to see that you are out having a good time. Only you will know when the right time is to start seeing someone. I have had great advice from family and friends, and they all tell me to give it around 12 months before I even think about seeing someone.
The emotional rollercoaster you have been on over the last 10 months may have clouded your judgement. You are in a very similar position (emotionally) as our S's were before they decided to have their affairs with "complete opposites".
Anyway, I hope I haven't confused as much as I have myself with my ramblings
I think all I was trying to say was to forget about H and what he is doing, and go out and have fun and do things for yourself now. What happens happens, its all part of life, so don't worry too much about it, enjoy.