In your interpretation of Church teaching,  you say:  "The greatest gift we have received is the gift of life, given by God, through the action of our parents, refusing to fully partake in His creation by deliberately denying another the opportunity of life, is sinful.".   
A gay Catholic is unable to comply with this idealistic mandate about providing for another to have the opportunity of life....unless that gay person was to enter into a heterosexual marriage, but that too would be a life of perpetual sin because the very fact they know they are gay mitigates against the validity of the sacrament.  Your advice, perpetual celibacy, is a choice that purposely denies another the opportunity at life.   In your understanding of  Jesus, LGBT are dam-ed if they do and dam-ed if they don't.  It's hard to see where any parent who believed as you do would see an LGBT child as a blessing.  Maybe that's why so many of our LGBT children are depressed, suicidal, and lucky if they aren't homeless.