You probably broke their community guideline terms and services policy and getting 3 strikes against you.
You can prepare an appeal to their decision. You may want assistance on this, say from a lawyer. Your slim small chances when doing this yourself are not good probably at all.
Best thing to do in this bad situation is get another Youtube account under a second Google email account.
I too violated Youtube policy and I know it can be a absolute nightmare especially if you have a Youtube channel with so many uploaded videos just to know you lost them all for good. Sometimes like myself I did not knowingly acknowledge that I had ever done such a thing to begin with.
Be sure to read everything in Google Youtube policies terms and conditions before you start a Youtube channel. Nobody wants to make the same mistake twice.