The Art You Like Looking At vs. The Art You Make
Learning the distiction between The art you like looking at and the art you make is incredibly helpful in building your confidence! Let's say your work is highly stylised and cartoony, but everytime you see a realistic painting, you feel like you should rather be doing THAT.
But if you're clear about who you are as an artist (what your influences are and how they reflect in your work), you can look at other art styles with admiration rather than jealousy or guilt. Learn to stay true to yourself and don't go chasing everything you see.
Of course, experiment and play, but don't try to become someone else.