No. I don't feel guilty. Seeing escorts has been a joy. I've had serious relationships and serious girlfriends. I love women. I just happen to be in a place in my life where it's hard to date. So, I just have to 'make do' having sex with beautiful women. Just because they're on the clock doesn't mean that you can't enjoy interacting with escorts, or the companionship, as well.
When I first started seeing escorts the experience helped keep me sane, and even now a good session with an escort is a delight that can put me in a happier place for days. I've joked about sex with escorts 'ruining' my sex life if / when I go back to dating, but the simple truth is that a traditional monogamous relationship fills other needs along with sex. (Though my good experiences with escorts may be delaying a push back into dating, if I'm being honest.)
Why would I feel bad? I get STI tested, and would make sure I was tested before going 'condoms off monogamous'. I would also do the same if I wasn't seeing escorts and just fucking randos. Would I tell a new monogamous partner that I have seen escorts? Probably not, but I would tell the truth and say I have an extensive sexual history, but I always practiced safer sex (for everything but oral), and have been tested regularly.
What's there to feel guilty about? You should understand that there is a stigma around sex workers and the people that see them, and act accordingly. However you really should do your best to let go of any sense if shame, or any weird notions about 'cleanliness'. (Christ, the number of non-pros willing to raw dog a stranger in this town is disturbing.) That's assuming you're thinking with your big head, being reasonably safe, minding your budget, and keeping your head on straight.
Seeing escorts should be a positive experience, if you're 'doing it right', and doing it for the right reasons. If it's not then that's on you, IMO.