Yes, start dating, don't know why you've waited this long. You're wife doesn't respect you, you don't have a lot of value in her eyes, if she shakes her butt in your direction she gets a rise out of you (re: your flirting remark) and it makes her feel really good to know she has all this power over you.
Move on, detach, do something that shows you're moving on. Otherwise continue to sit on this forum, mope about what she does to disrespect you and hurt you and keep asking people for input.
Here's a 180 for you.
Get all dressed up, go out, even if you can't get a date by tomorrow (LOL! that would be pretty quick), make it look like you're going out on a date. If she is around (haven't read your entire situation, do you guys still live together?), and she sees you're getting all dolled up and going out for a night on the town, she will be interested in your plans.
If she ask where you're going, smile and say "Going out tonight!", if she asks where, you say "Out!".
Seriously get some new duds & shoes, get the hair cut, put on the cologne, make it look like you're going out to impress someone and then go out. Have plans to do something, seriously, even if it's only to go the movies or take a very long drive for several hours, get out and start doing it.
You're a freakin' open book to her and she isn't hiding what she does and writes in her journal (because she has all the power in this relationship and currently pulls your strings). Start being mysterious, start going dark. If she happens to call or text you, don't reply back and when you see her the next day don't mention the missed call or text, let her ask about it and tell her "I was in the middle of something and didn't have time to reply back". If she asks where you went, you just say "Out" with a smile that shows you're moving on and you've finally realized that you've been wasting your time on her.
Continue being a great dad.
If she gives you issues over small stuff like bubble gum for your kids, you tell her that you are a parent and know what is in the best interests of your kids and don't need a lesson from her and follow up with "if YOU need MY advice, let me know otherwise you do your thing and I'll do mine - since we're planning to split up it's something you'll have to get used to".
She is used to you kissing her a$$, you can stop that at anytime now, the sooner the better. Show her you have a pair and you won't be bullied or pushed around or ridiculed. You respect yourself enough to let go of the people that won't respect you.