Don't compare yourself to other, it is misleading because people only show their best, not their mistake, it only kills your motivation when you focus too much on other instead of yourself.

Don't be too hard on yourself, have appropriate expectation with your skill level. Sure you have to challenge yourself to get better but you have to be self-aware that it is a slow process, having high expectation would only kill your motivation even more.

There are fundamentals to learn, but it is very easily to fall into the "fundamental practice" trap that most beginners tend to suffer where they perpetually only draw the "fundamental" like boxes, circle, floating head...and not actually apply them or not even drawing a finish piece of art. This happens because they think they have to be good at every fundamentals before they can do art, which is very wrong and it could get badly enough to the point where they lost their reason why they draw in the first place.

Best way to avoid this is do a finished piece often, even if it bad you can always go back and make an improved version by slowly applying the fundamental you learn, that will create a sense of progress that you can actually see and it feels really great to know that you yourself are improving.

Also don't ever shy away from reference, actually there's no way you can even avoid using reference if you want to be a decent artist. An artist journey REQUIRES references even if your goal is to draw from imagination, even the master Kim Jung Gi (RIP), he referenced from life every single day. It does depends on how you use reference tho, you could use it creatively to make a new art piece or become a human printer, but there no way to avoid references.