1. I think you should discuss those issues and worries with a therapist, sexologist, something like that. I would personally be worried by not being able to accept someone even 5 years younger than me, and to be so worried about appearance than being an "old" (big quotes) 30-year-old would make me desperate. Not to mention that t obe so centered on sex is probably not very healthy.
I'm not trying to ridicule you or anything, but I seriously think the issue is hardly aging but the fact that you're so afraid of it. Keeping yourself from visually aging is difficult, costy and everything but perfect. Working on obsessions, set ideas and rigid patterns however may be hard, but it's not costy, and it doesn't have the side effects of a lifting or a botox injection. Consider it. It's not like it takes anything away from you.
2. There are actually some young men who are into older women. They're even a "classic" fiction character.
3. There are ways to slow aging, such as avoiding the sun and eating well. Assuming that you're not so obsessed and that by 30 years old aging is already significantly apparent, you've probably not been taking care of yourself well. The worst I can think of is not protecting yourself from the sun, or even worse, actually tanning. At 30, in theory, your body has only been in a slow degradation state for 5 years or so. It should not be so apparent. If you start doing things healthily it shouldn't get worse too fast.
4. Although 30 is definitely a bit young, there are corrective surgeries and treatments for apparent age. Make sure you go to someone competent and discuss long-term issues with them properly though. For example, you may feel satisfied after a face-lift, but then realize that 5 years later, your stretched skin is worse than before. And uhm, no botox. Never seen it look even decent. There are also "soft" treatments, too, like skin resurfacing and such. Those are probably better to try at first.