I totally understand where you're coming from! I've felt that way a lot, but... it's slowly starting to fade. Y'know, after four years ;)
Honestly, sometimes your body doesn't work the same way other people's bodies do. I know that mine will just "forget" to use certain muscles, which is why I NEED to do strength training targeted to certain muscles- once they are being used and are getting stronger, my brain goes "Oh yeah! Let's use those things!" and it's good, but... yeah, that's also why I have messed up knees :P But I'm working on those!
Watching other people dance, it's sort of like looking at a painting- you can go to an art gallery and think "Wow, I could never do something that intricate!" and, when you go home and attempt to paint, you probably won't. You're looking at that other painting, the one in the gallery, with the kind outlook of someone appreciating art, the expression of another person. However, when you're looking at your own, you get the double-whammy of having somewhat less experience (my paintings look like they were done by a three-year-old, because that's about my skill level), and also having that big ol' critic in your head who only feels comfortable giving YOU the harsh critiques!
So, here's my tip: Only watch other people's videos for two reasons. First, for inspiration, as in "Wow, that's amazing! I'll keep dancing so I can do that move!" Or, secondly, for analysis. Such as "Hmm, I see how that person moved from one-handed to split grip! That was very nice, I'll give that a try next time."
Once you've gotten yourself out of the habit of comparing yourself to these other dancers, who are in different places in their journey, you can start watching just for the fun of it again ;) I'm still trying to teach myself those two mentailities for watching videos. It's tough, as I really enjoy watching just for the art of it... but, I'm very harsh with myself on critiques, so I'm trying to stop!
Honestly, keep at it! You'll be amazed at how your body reacts once it's done fighting you, and how much more you learn, all of a sudden!