This is definitely a daily struggle for me. Here are some things I have learned. Take whatever lines up with your experiences.
1.) Failure is normal, regular, and okay. The ones who make it the furthest have also failed the most. There's absolutely no shame in hitting your limits and I think it would be easier on everyone if we could all be honest about how often we fail.
2.) Depression will lie to you. It is the schoolyard bully that tells you you aren't enough, but it wears your face. Do not trust it to be correct. Especially about your success and/or failure.
3.) It's okay to take a break. And by that I mean a REAL break. Not just time off where you feel guilty the entire time because you're not making. Give yourself permission to rest.
4.) Sometimes the act of making is hard, frustrating, uninspired, and the final product feels so much less than what you wanted. That's okay. You still did it, and that matters.
5.) It's okay to take some steps backwards to adjust your direction. There's a feeling that going backwards is bad, because it's ground lost. But if you were heading in the wrong direction, the sooner you step back and find the correct path, the better. Sometimes old goals are unreachable, and new goals must be set. That is 100% okay.
6.) If you're in a position to ask for help, do it. If you're in a position to offer help, do it.
7.) Go small. Go very small. Smaller than that. Be un-ambitious (unbitious?). Don't plan a ten-year epic. Plan a single panel comic. Finish it. Then plan an entirely new single page comic. Finish it. Do another one. Maybe try two pages eventually. These will be building blocks to build you up to the bigger stuff, if you should ever want to. But you absolutely don't have to.
8.) Nothing is permanent. Even failure. Especially failure.