I have often heard people say that they no longer go to Mass because they can feel as close to God outside of Church as they do within it. A friend of mine, also, had the misfortune to suggest that if he switched unconsecrated hosts with consecrated ones we would still have the same "sensations" of Adoration.
Although God often gives us feelings of love and peace as gifts, or communicates to us expressions of His goodness through bodily or spiritual sensations, this is NOT the reason for us attending Mass and adoring the Eucharist. As Catholics, we believe in Transubstantiation, which means that the substance of the bread and wine is changed to the Body and Blood, Soul and Divinity of Christ while its appearance of bread and wine remain the same. God has commanded us to adore Him and to keep holy His sabbath day... this is why we go to Mass. Jesus has commanded us to receive the sacraments, because He knows they are necessary for our salvation, this also is why we go to Mass. We firmly believe that Christ is present under the appearances of bread and wine after Consecration, and for this reason we adore Him in the Eucharist.
God owes us nothing, and we owe Him everything. Intimacy with God leads us to and better reception of His love and goodness within us, and an increase of faith in His presence, but these should be accepted as undeserved gifts. When we pray and adore God, we do so simply because He is deserving of all love and praise. Therefore our prayer should be God-centered, not centered on ourselves and our emotions. In fact, love is an act of free will! There is emotional love, of course, but when we decide to love and serve and honor God... this is an action of our will and needn't have any spiritual or temporal feelings to be absolutely honest, unless our motives themselves are not pure. So, do not be lead astray by the magnitude of the gifts God offers us, or the reality of the spiritual, to come to think of yourself as deserving... rather, be constantly and completely focused on Him.