It's so tough when parents can't/won't accept something like this - sometimes this will be out of fear or guilt that they didn't do enough for us, or that they in some way are responsible for it. Once we're grown up, our focus changes, and the more important relationships are those we make "out there" - our friends, our workmates, but when we're young, the support of parents really does matter. In the meantime though, it's still worth finding out what having ASD means - whilst it's different for everyone, there are common themes. For me, finally getting a diagnosis meant I could be more accepting of myself, and suddenly all the difficulties I'd had as a youngster made sense: I can stop being quite as self-critical as I have been.
There's always a balance of advantages and disadvantages in thinking about getting a diagnosis though, and as others have said, the advantages include being able to ask for reasonable adjustments to be made. We shouldn't forget the positives about being autistic, either - we're often creative, meticulous, good at detail and pattern recognition, and our different way of viewing the world can bring insights that neurotypicals are less likely to see. As far as suitable jobs goes, that one varies from person to person, not least because it really is a spectrum: in a way, it's more about the effort we need to make to adjust to a neurotypical world, and how much that stresses or tires us, and how we respond if we are just too stressed or exhausted. Hooray for the internet on this one, it opens doors to us, as we have options to look for work where we don't need to be in busy crowded spaces, where we can write rather than speaking, and, being unseen, won't be judged for the way we dress or interact.