I can comfortably work pretty much any muscle and feel the burn/see results after persistence but for some reason I can never get anything out of my shoulder.

I started off with the shoulder press machine and that did nothing so i switched to dumbbell press. That worked slightly better but just felt like I was doing my back more than shoulder. Any suggestions?

if you are sitting straight up and pressing either the DB, the machine, or barbell straight up then you were definitely working your shoulders. If you felt like you were working your back you're form is off.

other good shoulder exercises are upright rows, lateral and front raises, and bent over flies.

You're obviously not hitting the hitting the front deltoid head. You have to retract the shoulder blades in a 180 degree angle to hit the anterior deltoid. Also try keeping constant tension by not locking out and only coming down to about mouth level.

Keep in mind you three deltoid heads. Hit a lateral raise for a medial head.

To hit the posterior deltoid make sure you're already hitting several rowing exercises you could also try hitting a reverse fly or face pull

Ditch the upright row. They internally rotate the shoulders.

Heavy clean and press
Wide grip upright rows (best side delt exercise, and doesn't hurt the shoulder)
Bent over dumbbell laterals
Standing side dumbbell laterals
Machine presses, preferably with a hammer grip

Your shoulders will get big.

the shoulder press will hit all 3. im also a fan of the lateral raises, standing/seated/bent over/facing on an incline bench. uprgith rows too.

also when you do chest execises, your front delt gets a good work too.

i have this problem too, my left shoulder gets fatigued so fast since i broke my arm on the humerus, right under my shoulder

i dont know if this has a real name but, sit at a bench with around 10lbs dumbbells to start. hang your arms straight down, with your elbows locked straight the entire way lift the weight above youre head. either to the sides, in front of you, or alternate.