It can be difficult when we feel like our fellow Christians aren't acting very Christian toward us or toward others. The Church is indeed made up of sinful, imperfect people, who often disappoint. But rather than distancing yourself from the Holy Eucharist and the Catholic Church that Christ founded, consider clinging to Jesus all the more, since he never disappoints. It is helpful, in times of trial and hurt, to remember why you are Catholic—not because all Catholics always represent the mercy and love of Jesus perfectly well, but because the Catholic Church was founded by Jesus, administers the sacraments, and contains the fullness of Truth, helping all of us to draw closer to God and grow in holiness. Do not allow the actions of some to cause you to lose faith in the Church as a whole. Discuss your frustrations with a priest or deacon at your local parish, and start your journey back to a welcoming home. Above all, do not lose heart. People may disappoint, but God never leaves us, and He is always present in the Catholic Church he founded.
See Darren's testimony about leaving the Church and coming home.