with a girl who isn't a prostitute

uh okay

its easy to tell them apart from students or other girls just doing this on the side

sure it is. This is just like my ex being cool with not wearing condoms with one-night stands because he could tell if a girl had an STD by looking at her face. You can't tell a sex worker by what she looks like or what she says. Plenty of people can't even tell a sex worker who has been forced into that line of work from one who is there willingly. Paying for tuition is a common excuse used by many young women because it makes men feel better about themselves and what they are doing. I'm just saying. Don't delude yourself or have aspirations that what you do is somehow better or more moral because they're allegedly in college and you're spending some more time together.

I am starting to wonder if this is hindering my mindset of finding a real connection

Probably so. Firstly, by knowing that you have assured companionship available, you're probably not putting yourself out there. Secondly, you're probably unknowingly gaining a lot of habits and behaviors toward your partner that will put off the kind of woman you eventually want to date and maybe marry - unless you want a sugar daddy/sugar baby type marriage. In which case you're cool, you do you.

And yes, do disclose this to future partners, because if you don't and it comes out later, you could be in for a hell of a time and it's better to figure out if your morals align before you get so invested that a breakup feels like it's ripping your life apart.