Hey
I would love some thoughts on ho to approach my dilemma. I will in advance apologies for any language errors.
Background story:
My girlfriend(20) and I(22) have been exclusive for 14 month. We both study full time at in the same city, I have my own apartment while she live with her parents. Through our time we have had our share of relationship issues with, in my opinion, we have dealt with with a nice outcome. We have a fine sexual life, where I am the dominant and the one with the biggest sex drive.
1. Dilemma:
My girlfriend suffers from endometriosis, which once a while requires us to lay of sex for a couple of days, due to pain if I penetrate her. Due to endometriosis have worsened, we haven't been able to have sex for 2 months. Mostly when she is on her period or we can't have intercourse she enjoy giving head. But these 2 months with out sex she hasn't given my "special friend" that much attention. She have maybe twice grabbed it with her hands, wanked it a bit(lasting less than 1 minute probably) and just stopped. She hasn't been into cuddling which she usually loves when we sleep together. I know its tough for her, and I had taken a little talk with her about it which just leads to her saying she doesn't want me to get aroused when I can't fuck her.
1. Question:
How to handle this kinds of periods with no sex? I have experienced that I flirt a bit more with other girls than I usually do, to a point where, from the look on the girls, got disappointed when I said goodbye and left without asking them to come home with me. I have caught myself in fantasizing, while jerking off, about fucking these other girls, take them home with me and cheat on my girlfriend with these girls.
How do I bring the more sexual flirting back into the relationships and how do I make sure my needs are needed?
Bonus question: How to make my girlfriend, which is daddys little good girl, try experiment with sex? Like anal, costumes, sexylingerie and stuff like that? Any guides? And my own problem, can't reach orgasm by oral sex, even though I am in seven heavens I just don't finish, and thoughts?
Any comments, links to articles concerning this and advice are much appreciated

Thanks in advance!
If needing more information just ask and I will answer.