I fixed everything. Please, if JOSM says that you have 1000 errors, don't upload it. There are some false positives, but usually JOSM validator is right. You should ignore a warning only if you are sure it's a false positive.

Uploading a backup is not a good solution, as you just created duplicates of point, there were a lot of separate points at a same position, I guess they came from your "backup".

If you are not sure what you modified, it's recommended to upload more frequently, in smaller changesets. Maybe draw buildings on 1-2 streets, than upload. It's easier to manage and check smaller changesets. 