Thank you all for your advice- it really helps! I did read DB about a year and half ago when we had our first crisis period- didn't know it until now but apparently he was having another affair then. I applied some of the tactics but probably backslid as things got better in the relationship and then worse again. Have started reading over again. Lately I have been a total doormat, pretending that I don't know and trying to win him back by initiating phone sex, applauding him for EVERYTHING, etc. because he claimed I was being selfish and didn't really care about him. (SOOO not true, clearly I would not be here) But... I am just now realizing I was continually going down the same cheeseless tunnel- I would compliment him, get a smile, which would make me feel good, but that wouldn't turn into anything more. I thought by making him feel good, he wouldn't need to turn to another woman to make him feel good, but apparently she's doing something for him, and pursuing him and it's working for her.
Here's my question for you all now- what about confronting him? I have decided not to call him, have even temporarily turned my phone off, but I have to tell him that I know what's going on. I don't want to handle the matter over the phone but he lives halfway across the country (we are in a LDR) and I know that going there would be even worse, so how do I communicate to him that I am not answering the phone because the cat is out of the box? I would like to just say to him that I know he is involved with another woman and that he needs to come clean and whatever he says just say to him "when you want this marriage, you come talk to me, and make a commitment to working through your issues with a therapist, not through affairs." and THEN go dark. But do you think I shouldn't even do that?
About the MLC, he IS young, however exhibits HUGE insecurities and preoccupations with growing old and not achieving certain things by his age (maybe that's why he married me?), started working out and obsessing about eating well (I think the 1st OW was a nutritionist and fitness buff), etc. Has cycles- is somewhat dependable, unhappy but optimistic, dreams and schemes with me about our future plans together, tells me he's dying to have kids and is impatient for me to finish school to have them. suddenly becomes horrified at any responsibility. he doesn't want a mortgage, or children, or marriage. This is the 3rd cycle and the first time I've discovered infidelity, which is my boundary line. I just don't know how he's going to get that I know about the affair if I don't tell him- he'll think I'm just blowing him off for no good reason. What to do?