One cannot feel as one with Hashem and to truly feel the truth of his "One-ness" as long as one is not clean of the desires of this world ["tyvos"] and particularly the sexual urge as the pasuk says לתאוה יבקש נפרד - Tyvos want to be SEPARATE.
On the other hand, the more one instills within himself the knowledge that Hashem is One - the more his tyvos are minimized. If one feels that tyvos are overcoming him he should not despair. Rather he should think about how all of existence is Hashem and this tyva will just distance himself from true life and put his neshama in a dark, impure place. ולבבו יבין ושב ורפא לו - His heart will understand and he will be spiritually healed.
People mistakenly think that when they deny themselves complete fulfillment of their desires they are doing the "right thing" even though it is not for their benefit. Their benefit would be to do whatever their heart desires but, what can we do - there is a moral code that we must follow. The truth is that the WORST THING for a person is to succumb to his animalistic instincts. We see this in the world. People who are just hedonistic pleasure sekers are unfailingly miserable.