Wondering if she truly loves me or I am used as a fool for love.

Hello pals. I am 25 and she is 23.I have being dating a lady for the past 4 months. I got to know her 4 years back and never took the chance to ask her out. After some couples of breakups on both sides we came back together and got serious with each other. She happens to be having a kid 5 years from her past relationship claiming from her first love. Am cool with that and tried my best to support her with the little i had, since the father of the kid wasn’t providing child welfare i tried and appreciated everything about her. During the course of time she introduced a certain married man who she claims is helping her. The mans wife and kids are in another region all together. My lady falls on this man for almost everything without my notion and even to the far extent of so close to the man that he visits the man in his house, Cook and wash for the man and to come and pick up. I sometimes sit and watch their late night long phone conversations. All the troubles started sometime when she refused me making love to her, with some funny excuses and as usual brought some misunderstandings between us. She told me point blank that she doesn’t care if i go and satisfy myself outside. But till now i tried my best and never got myself dirty. I am wondering if she truly loves me or i am being used as a fool for love.