Its hard for me to tell if I suck or if Its normal to lose this much.

trying to climb to D4 has been really affecting my mentality. this game is actually making me feel stressed. I cant tell if im losing games because im to bad to climb or if its just league trying to balance my wins with losses. maybe i only made it this high by luck and now im losing to fall back to were i belong in plat 4 or something. I lost my promos the first time and now i cant even climb back to try again. any advice from the community would be appreciated.