I did it. I like you felt like the life was being sucked out of me, I didn't leave I got a court order and made him leave. It felt good, I felt brave, I detest change, I took the bastard back after he threatened suicide,promised change and lots of other crap but mainly for my DC. 
Then 8 months later he left me to live with his new Miss Affair No. 2.
Think it through, weigh up pros/cons, try to imagine life without him, financially, emotionally, talk it through with friends, work out the practicalities, think how you would feel if he left you, would you be heart-broken ? I was. Then I seen the light. I think it hurt my pride more than anything tbh.
He wanted to come back.
I said no. Then yes, then no no no no.
I am very very happy being a single parent.
The only few draw backs are I miss someone being here so I can have a bath in peace and possibly the money.
The house is so much more peaceful, no stress, no resentment (re: affairs) just me and my happier boys. I do occasionally miss cuddles but have a great electric blanket and sometimes have a little fling/date if I really need a cuddle! I answer to no-one, do what I like, when I like, I love it, so much so that I really cannot imagine ever living with anyone again, I know this may change when the DC grow up and leave me (sob) but 2 years on I am most definitely happier on my own.
Just think hard about it. Could you explain your resentment over his affair and suggest a trial seperation?