1) I have a family doctor. He does walk-ins and takes appointments, as do most GPs (General Practitioners) in the Windsor region.
2) When going to a walk-in clinic is my only option, my overall experiences have been satisfactory. That said, walk-in doctors can come across as rushed or hasty but it's important to understand that a) they're professionals who have gone through many, many years of medical schooling and b), even the best doctors misdiagnose patients occasionally.
3) Don't self-diagnose yourself. The majority of the time your self-diagnosis will be wrong, and you'll end up needlessly stressing yourself even more.
4) Doctors make mistakes-- I can't stress this enough. When an issue is very serious, doctors put more time into a more thorough diagnosis but when an issue isn't relatively serious, the unfortunate truth is that doctors won't take as much time to engage in a thorough diagnosis. I realize doctors are almost viewed as superheroes, but they're not without flaws so I ask that you please don't disregard walk-in clinic doctors because of one or two bad experiences.
5) Send me a PM-- I've worked with medical professionals for several years now and I would be more than happy to point you in the direction of a good GP (general practitioner)/ family doctor. All of the GPs I know do walk-ins in addition to taking appointments, and they're all highly respected within the medical community.
So to conclude, if there are just two things you take away from my long-winded comments, it's that a) don't self-diagnose and b) understand that as /u/gundam501 said, there are good doctors and bad doctors-- good doctors can have bad days, and bad doctors can have good days.
ONE LAST THING Doctors hate it when a patient self-diagnose himself/herself and then expresses doubt when given their actual diagnosis because it doesn't line up with what they saw on WebMD. So trust your doctor-- they're far less likely to make a mistake than you are, as long as you are 100% honest to them.
(Also if anyone else reads this, I ask that you please refrain from PMing me for a GP recommendation and that you go to any of Windsor's walk-in clinics. I'm just doing this as a one-time favour to the OP.)