So, it isn't as if you have a candidate in mind, then? You just want a long-term, serious relationship, family, all that?
There's nothing wrong with wanting that, and nothing wrong with trying to get it. If the candidates in the pool you've been fishing do not cut it, then yes, you need to expand the parameters of your search, which may very well include an older man. There are a lot of older men who would definitely be interested in a younger, attractive woman, and they ideally have some degree of experience, maturity and stability, which sounds like what you want.