Sounds to me like You know exactly what is causing You problems. If You need help understanding, You need to ask for it. I would expect that the school You are studying with would make every effort to help You succeed. Especially if online learning is a new thing that the school is doing due to the pandemic, but the truth is, You have to be the one to ask for help.
Part of being a successful student is being honest with your teacher. If You never let your teacher know You are not understanding, they can not help You. Get over your shyness and self doubt and speak up, honestly when You think about it, what is the worst thing that can happen if You do that?
As far a procrastination goes people don't procrastinate over things they want to do, or are interested in, unless they are struggling with doing it or understanding how to do it.
Tough love might also be what You need to hear. So don't take this the wrong way but, "Suck it up princess!" succeeding in life is hard work, if You really want something in life You have to make the effort to get it. There might be people willing to support You right now but as life goes on and the older You get, those people will become few and far between. There are no paricipation trophies for grown-ups in life, so stop making excuses and knuckle down and get to work. Or don't and keep feeling like a "loser" at the end of each day.
Finally if the task seems insurmountable or You have put it off for so long that You now feel there is no way to do all the work that is needed to be done. Here is a joke/trueism that might help:
Q: How do You eat an elephant? A: One bite at a time!