Hmm. I'm not necessarily hearing abuse here -- Am's husband may be being brutally honest. The "chip on the shoulder" comment? Well -- isn't it true that if he gives up the gf FOR Am, he will be resentful?
Am, I commend you for giving it a go. No matter what happens, you are going to learn so much about yourself. You may be unclear about what your boundaries are, but what they "should" be can only be determined by YOU. The people on this forum are here to give our opinions, and you are free to take what you like and leave the rest. I think it is helpful to consider all the perspectives, though -- because there is some real wisdom here from the personal experience of others.
I think it is wise to put yourself at the top of your list right now as far as doing things YOU like to do, and giving your SO lots of space to figure out this relationship with the gf.
Yikes, I also think when people cohabitate out of financial need, it can distort the true nature of love, in its freest form. Hard to be with someone you "need" to be with, instead of purely because you WANT to be with them. You are all in a complicated situation. I'm feeling for ya.
Also, regarding the PMS statement? I tend to attribute that to ignorance, rather than malice. We have a whole generation of people who have learned that PMS is a great way to explain things that are confusing to us. It became a convenient excuse not to really listen and try to understand what women are really thinking and feeling. I hope your husband will open his mind a bit and choose to become enlightened! Otherwise, well -- maybe the gf and he deserve each other - ?!