To the OP:
I think it's very hard nto to be influenced by the way noncatholics define us. They tend to think the church's teaching on sexuality is its most important feature, whereas for us it's more usually the mass. I'd say if it's mass that you love, just go wiht that and don't expect the Church Militant in the world to be too much like the Church Triumphant in heaven
A thing to say on sexual teaching might be that while the church condemns gay sex, but not gay men or gay love, it also condemns any sex outside Catholic marriage, which means the vast majority of sex currently taking place in Britain this week. Gay sex is no worse than and no better than ordinary nonmarital or extramarital sex or any sex practised in an effort to avoid the conception of a child, or even sex within a nonCatholic marriage, if you are really really strict.
Alternatively, you might say that Catholic marriage OR celibacy are ideals, and difficult ideals for some (most?) at that. I'm really sympathetic about mistakes in this area because I'm so rarely tempted. Greedy eating, now... and envy.. much more my besetting sins. This is really just luck, and I'm not especially pleased with the fact that i'm lucky enouygh to be in a catholic marriage - just dumb luck, or grace.
I suppose you could say that just as homophobia is a mortal sin, very serious, so too is fastbreaking, having a lie-in on Sunday, and a determination to pursue your own desires regardless of the consequences - as some but by no means most gay and het men did in the era of incurable AIDS. Only God could say which of these others are serious, if any. But anything which has a negative impact on you or someone else is worth avoiding where possible.
What Jesus did say on earth was that only he who is wihtout sin should cast the first stone at a woman convicted of adultery. But the Pope also has to provide moral leadership on the ideals, as well as offering love and hope to anyone trying to rethink their life.
Obviously, almost everyone nowadays is going to feel excluded by this body of teaching and it's not the first thing a Catholic might want to talk about when describing why we keep going back to church, and it's not the first thing the church is apt to ask of anyone. But until recently this idea - lifelong commitment and raising a family - was most people's aspiration, for better and for worse, indeed. It's debatable whether everythign is better now with a 50 percent marital failure rate...