Walk-in or ER?

So I have a few little things that have added up over time and I think I need to sort things out. My only problem is I live in Canada in a city where family doctors accepting new patients are a myth.

  1. I can't catch a full, deep breath. This has been ongoing since December 2018. Makes it difficult to exercise, play with my dog, swim, etc. I also have a pretty physical job so I get slowed down.

  2. Over the last 8 months I've developed really bad acid reflux. At first I was able to control it with some tums here and there but now I have to take pepcid every morning and tums minimum once a day. I used to have IBS, no idea if I still do/if it's a contributing factor.

  3. Yesterday at work I was sitting on my lunch and for 15-20 seconds out of NOWHERE my heart started racing and was beating so hard my whole torso was rocking back and forth.

I'm overweight, don't exercise much outside of a physical job, don't eat as well as I should, and haven't had a proper checkup since I was probably 18 (the last time I had a family doctor).

I'm aware that most of this can be explained by high stress and bad diet/exercise. Which I have. But I'm worried that years of my not-the-healthiest lifestyle has done lasting damage especially to my heart. Most of these things require tests and followups, which walk-in clinics don't typically do. I don't know. Just looking for a little direction, thanks in advance.