I lived there for a couple years and I met this guy who has bought and managed a ton of property there. 

You would have to self-manage though, as paying a property manager will eat up most of your profits.

While short-term rentals in areas like Kissimmee, Florida, can pay for themselves and offer lifestyle benefits, the ROI typically doesn’t match what I see from my traditional portfolio of long-term rentals in North Texas.That said, short-term rentals can still be a great choice, especially if you're drawn to the area and the opportunity to combine personal use with investment income.

As the owner of a property management company in Washington, I have encountered this situation before.

If a HELOC isn't an option due to Texas laws, you could consider a cash-out refinance with another property or a portfolio loan, even if you want to keep your current rate.

Sorry to hear your self managing isn't going as planned...finding good tenants is tricky!

Then you can manage the calendar.

As for the rest of it, you can find a lot of useful tips on past forum posts along with podcasts and youtube material on the topic (BP and other RE sources).We've self managed STRs for a few years.

Self managing should be easy, if not then that Realtor can probably help you with the rental side of it. 

Not sure if you have a single STR or manage a portfolio, but I’m only managing one STR right now, and wondering how to set up that kind of payment?