"that's why there is a word for it" Well that particular word actually is far younger than thousands of years: http://plato.stanford.edu/entries/homosexuality/
Kinda makes you wonder a little bit our current distinctions and their actual relevance to the human condition.
"you may have to accept gay marriage, even if it violates what you feel like marriage is" What you feel like marriage is has nothing to do with what it actually is, which is a very well-defined legal construct outlined by the state. Your feelings are valid in a different context perhaps, but when it comes to the legal definition it's not a compelling part of the argument. In that context, a great many arguments have been heard in court and gay marriage bans have been roundly rejected, many in a bipartisan decision.
"If homosexuality is an unhealthy expression of sexuality, you won't want your kids exposed to that" Kids are going to be exposed. Gay people exist, and kids will and do meet them. Some 2-6% of the kids in that sex ed class are going to be gay themselves. Not saying parents shouldn't have a voice in this, just pointing out that prohibition is dangerous. You can't hide the word gay from children, and denied knowledge often only serves to generate greater curiosity. I would hope some clinical information about how to be healthy and gay isn't asking too much of these fragile creatures, but perhaps heterosexuality is really hanging from a thread? Somehow I doubt that.
I suppose it does. But if one of your children should happen to be gay, you've left no question, from what you've written, that you won't hesitate to push heterosexuality on them.
We care more about them finding a path to self-acceptance than we do about your prejudice.
I doubt anyone can do anything to change a paraphilia; pushing normative sexuality on someone is unlikely to be productive.
But I don't think self-acceptance is a good goal either. There are many unhealthy things in each of us; we shouldn't accept them, but rather should fight against them. I'm naturally lazy; I like to eat a lot; I'm selfish; I talk over others—I have to struggle against each of those deficiencies.
Due to this change in society, it is difficult and becoming more so to marry in the older sense. The more people who adopt the latter meaning, the fewer will retain the older. And even those who think they do are inevitably influenced by the rest.
I don't care much more about two homosexuals claiming to have married one another than I do about someone claiming to be a prophet or the reincarnation of Galileo; what worries me is the continued removal of any meaning from marriage.
Also, the lifelong nuclear family is something that only really appeared after the wars. Pre-war there was no antibiotics and the rates of female death were so high that single parent families were much more common than they are today. If your worries about developments in marriage are that it will reduce the stability for the upbringing of children, I would like you to consider which eras you are choosing for comparison, as we are now living in an era that supports longer childhoods than seemingly at any other point in history.
edit - for the complaint that it is difficult to find more traditional people as spouses, may I point out that there are a number of other people who seem to be making that complaint. Presumably you could find their parental address, so that you can appear in person to make a formal request to their father to begin courting. Oh, and remember to bring some cattle.
I definitely feel like there is some amount of "pushing homosexuality on everyone" that has been going on the past five or ten years. It's no longer socially acceptable to think that homosexuality is wrong or an unhealthy sexual expression. Even donating to an anti-homosexuality lobby can get you pressured to resign [1]. Depending on the state you live in, you may have to accept gay marriage, even if it violates what you feel like marriage is. I don't know if sex-ed in schools is teaching it yet, but if not, I assume it is just a matter of time. If homosexuality is an unhealthy expression of sexuality, you won't want your kids exposed to that, but, no choice.
For people who agree that LGBT is acceptable, this probably feels like progress. For people who view LGBT as unhealthy sexual expression, the net effect feels a lot like "pushing homosexuality" on us.
[1] Brendan Eich, former Mozilla CEO