Negril I am so sorry you are here but there are many good people here who know exactly what you are going thru and will be here for you.
Just from what your saying, It is my opinion *and I am NO EXPERT*, that your wife was craving attention from others and got that need met when she started school. I too never got the attention from my mother I needed and I had no sisters, so I crave that also. This is just my opinion of course, but that led to hanging out and then one thing led to another. Sounds like she is enjoying all the attention and I am sure that is boosting her ego. Prb MLC but it doesnt matter. You have to leave her alone to do her thing regardless.
Also, you have a right to be angry about her staying out late, dont question that. Dont let her put the blame on you, she will try.
Read all you can to understand and come here for support.
This could be a long road so hang in there.
Prayer helps also. Ask God for peace and strength.