<human>: Give me the gist of the text in a nutshell

We are dating for more than 8 years now, and we are each others' first relationship. We have an incredible amount of harmony, we understand each other in ways no one can and we completely trust each other. 

The problem stems from the fact that she has much higher sex drive than I do. She also takes rejection very negatively, and feels awful when I reject her advances. So for all these years, I have been faking lust and enthusiasm for her. She asked specifically a couple times if I have ever faked interest, and I did not have the balls to tell the truth, this has gone too far.

I like our sex only because they are great opportunities to make her very happy with relatively small effort. I just have to concentrate hard to be able to come when she is going down on me(after she is satisfied). 

I don't mind the sex life and I can usually deal with its stress with a nice jog, but I feel guilty for lying to her for so long. Is confessing to her ever a good idea? I fear she will never truely enjoy sex with me if I do.
<bot>: GF of 8+ years like sex, I don't but I kept pretending to like to make her happy. Shall I tell this?