The database is broken

The main site (root node) won't allow me to post or create categories
I did once make a change to the database though. Editing the wp_users table, the id's. Primary keys
The only problem is that it has almost 2000 posts. When I transferred the posts into a subsite, all the users weren't linked to their posts anymore cause the ID keys changed. I could try and reinstall, but is there a better way to handle users content?