Costochondritis is unfortunately, not widely known or discussed and I've got more information from here than my gp.
Although I'm lucky to say I'm 80-90% healed, I've reached a plateau.
I wanted to share some of the less common symptoms I've experienced in my healing process for those who may be scared/confused:
Dizziness
Head pressure on the side of inflammation
(possibly led to a slowing down of the movement in left eye, I now wear glasses to refocus, never had eye issues before)
Headaches
Swollen neck
Tightness in neck
Swollen shoulder muscles
Back pain in the middle of back
Inability to eat
Feeling physically full after half a meal but still hungry
Stomach pain
Burning sensation in muscles
Tingling sensation in muscles
Strange sinking feeling when breathing, comparable to the stomach drop you get in fear/on a rollercoaster or similar but it's more muscular/physical
Sensation of muscles suddenly "deflating" when falling asleep - possibly anxiety related as well
Constant palpitations
Fatigue
Tiredness
Generally weak
Arm pain on side of inflammation
Feeling like I can't breathe
Difficulty walking at speed - who knew swaying arms could be so painful?!
Feeling fine all day but swelling up when you lie down to sleep
Sinus pressure
BONUS: For those who have overcome the majority of the pain
general discomfort/awareness/heaviness/tightness of the affected areas
Feel free to share your uncommon/less discussed symptoms