@jdbarr1
Deep breaths and coughing certainly aggravate costochondritis so that may be where the smoking and virus played a part.

I was 18 when it hit the first time. It was my third karate class in college PE when I thought I pulled a muscle. Horrible pain for 2 months. A few years later it flaired up again and I was diagnosed with costochondritis. Avoid major stretching, even when reaching for something on a high shelf. Gentle upper body exercise that doesn’t strain your ribs.

A physical therapist would also be a good option if you get one that is very hands on. Again, it’s the manual manipulation that helps. I didn’t do PT for costochondritis , but in recent years I’ve used PT for post-op issues and found it very valuable with some therapists more hands on than others. PT may be easier to get than osteopathic manipulation. I think you are spot on that with either one you want to find someone who has successfully treated costochondritis. Most doctors don’t understand just how painful it is. I can’t even take any meds for pain except Tylenol that does nothing for any pain I have. You don’t want to get hooked on anything though.

Michael Jackson got costochondritis in the middle of his intense dance routine and went to the hospital by ambulance believing he was having a heart attack. His heart was fine, but he stayed in the hospital for a week demanding more tests to figure it out because he was scared by the pain and thought surely he was dying. We get that, right? It’s soooo painful!!!

I was in my late 20s before I discovered that it doesn’t hurt other people when they touch their ribs. I was stunned to learn that. When my son was about 10 he gave me his tightest bear hug with his arms around my lower ribs. I thought I was going to pass out from the paralyzing pain. I couldn’t even speak to tell him to stop.
I hope you can find the right hands on therapy to fix this and then be aware of what triggers it for you to minimize episodes. I also have a lot of rare physical diagnoses so I get that frustration too. So does my son and so did my aunt. Lots of genetic mutations. Such is life. You’ll be okay. Practice good health habits. Get involved in fun healthy activities with happy people that bring you joy to reduce stress. We have to do our part too.