I am so sorry that you are dealing with this. Four years ago I found out that my husband was frequenting asian massage parlors for happy endings, had a porn addiction, masturbation addiction and was sexually abused when he was eight by a female relative.
Like you, I was in total shock, totally blindsided. Initially thinking, "what did I do to drive him to this? Am I a bad wife? Am I too fat, too ugly, too this or too that?"
We also had sex very infrequently (called sexual anorexia).
The thing is . . . it had NOTHING to do with me. It has nothing to do with YOU. You were blindsided by this.
My husband is a recovering sex addict. You might want to look into this. Some of the behaviors your husband exhibited raise a red flag to me.
Sex addicts often start out with porn or masturbation addiction. When that "high' from that no longer satisfies them, they move to the next level (massage parlors). When that "high" does nothing for them, they head to the hookers. They compartmentalize what they are doing -- in their brains they think "this part of my life is on this shelf, my family is on the other shelf."
Sexual addiction is a cycle. They may feel stressed/depressed. They never learned coping skills as children (many sexually abused and/or had emotional midgets for moms - mine did). So they start thinking about getting "high" to relieve the stress/depression. They act out to relieve the stress. After they act out they have a feeling of shame which leads them back to stress/depression. shampoo/rinse/repeat.
If you think he may be a sex addict, you can go to the website recoveryzone.com There you will find a sexual addiction screening test (SAST) that may help.
I don't want to overwhelm you,but what he has told you so far may be the tip of the iceberg. It took about 4 months of trickle truth (TT) for me to get the full truth from him.
My husband attends a 12 step group,and IC. I won't lie to you. It is very difficult living with a sex addict. BUT-- if he is one-- and he works the program things can get better.
He needs to be totally transparent with you. You need all passwords to everything -- phone, computer etc. Tell him you want to run a credit check on him(you just need his SSN and his permission to run the check yourself). He may have secret credit cards or outstanding loans (my husband had both). Look at every charge on the credit card statements going back a few months. Also go through phone records. I also put a keylogger on the computer.
In the meantime, as others have said -- you need to take care of YOU now. Make sure you get tested for STDs.
There is a great book for spouses of sexual addiction called "Your Sexually Addicted Spouse" by Marsha Means and Barbara Steffens. That book helped me understand a lot.
I hope I have not overwhelmed you. There are so many wonderful people on this website that have helped me. There is a thread in the "I can relate" forum called Spouses/partners of sex addicts. Everybody there is great. We understand.
You can PM me anytime.