I would say never give up, because even if your friends can do X that you cant, fc or what ever, if you focus on yourself and try to enjoy the game you will eventually improve.
Look at my profile, i played for 6 years and i'm still 15k, and i'm in the same position as you, i tried everything.
What i suggest you is:
-Try to write down your bad habits and common errors, things you are not good at and look for a solution for them.
-try to play lower difficulties and see if you can fc them.
-Warm up with some DT and play some HR, it will make you improve a lot.
-Play high bpm maps, DT >145 bpm maps (220 with dt), streamy maps and jump maps.
-Compare your results with yourself, if you find you are worse than yesterday look what you are doing wrong or what is different.
And finally: Enjoy the game (and dont break your tablet).
Ah, also... Try to play confortable when you use your pen, if you force it or if you apply strength it will make you play worse, try to play smooth even if you dont aim that good at first, you need to use your own speed, not your strength as speed, less strength = easier to snap.
I hope it helps a bit