Hi, @IvanAlej ; welcome to the forums.
Sorry to hear you’re having challenges finding a sitter. I’ve had a look at your listing and I don’t know that I’d say you’re doing anything wrong per se. Your home seems tidy, pets are cute & care requirements seem reasonable, your tone is friendly, etc.
I suspect it’s more that you’re a victim of the current circumstances, with the recent TSA issues, the war, the economy, price of fuel etc. hindering travel plans for so many. If you have a look over the forum you’ll come across several threads where these issues are mentioned, alongside discussions of cancelled travel, increased costs, and a dearth of available sitters to meet the needs of active listings.
That said, a couple suggestions off the top of my head (and I’m sure you’ll get a number of others from the many experienced folks here:) 
— First: make sure you have a backup plan in place, be it a paid sitter or family member just-in-case. A lot of people are finding it necessary to cancel plans due to cancelled flights etc., plus your dates aren’t terribly far out at this point so it’s probably time to think about contingencies if you haven’t already.
— You don’t mention if a car is required, although you note the HEB is 7 minutes away, so sort of implies one may be needed. Is there any possibility you can provide the use of a car as part of the sit? With increased travel costs, the savings on a rental car could be a significant differentiator between your sit and someone else’s.
— Your pets can be left for up to 6h; maybe include some enticing suggestions (w/a few photos) for things sitters might find interesting to do in your area? I don’t really know the San Antonio area…I’ve heard it’s nice, but wouldn’t know what kind of outings/restaurants/experiences/local events you have nearby that might make me want to visit. Perhaps include some that can be done with & without the pets.
Last, if it does come down to the wire: the Forum has a ‘last-minute sits’ category that you can post in if you haven’t found anyone within 14d of your start date. Hopefully that won’t be needed, but good to be aware of if you do.
Best of luck!