I agree...so not your fault but I think we all experienced that emotion at one time.
I filed for legal separation 6 days after DDay. I found the forms on line for my state and had my WH meet me at the courthouse where we jointly signed in front of a notary. No attorney necessary if you can get him to cooperate.
I pulled my WHs credit report on day 5 and found that he had been racking up serious debt for last two years. If he has been sending her money you might want to check this too.
The legal separation does everything a divorce does, you just can't get remarried without a divorce and you can stay on a joint insurance policy. May give you the time you need to decide if this is what you really want. I sent you a personal message if you'd like to discuss further.
Also, I think a pink duvet it a great idea. Got mine yesterday but it's purple I'm a survivor, I'm gonna make it, I will survive, keep on surviving...
BS: me 42
Married 18 years
D-day - 1/11/14
Filed - 1/16/14
Walked in on WH and BF while her H watched