Hi, welcome to SI. So sorry you find yourself here.
Kudos to you for finally saying enough and walking away from this toxic relationship! Serial cheaters rarely change.
There are meetup groups all over the country, I think the website is called meetup, not sure, but check them out, there are tons of activities based on your interests and many times just people who moved to the area looking to make friends.
Another member suggested volunteering, I volunteered at a local animal shelter for a couple of years, it took my mind off the hell and was also so rewarding. The shelter I volunteered at had a program for teens, they met once week, taught them basic animal care and they helped mostly with the cats getting them out of their cages and helping them get much needed exercise. There are so many opportunities to volunteer, a call center, food bank, etc.
Suggest your daughter get involved in extracurricular activities at school, that's a great way to make friends. Also check with the school counselor, he/she might have some suggestions.
Are you and your daughter in IC? Sometimes you just need a little push from a good counselor to get your life back on track.
Please read the Healing Library and post as often as you need to.
There's also a divorce forum where you will receive support from members here who have had to walk away from the marriage.
Sending a virtual hug....