My sitemap says it has 54 error pages (these are all old urls that i changed) however after i changed the urls names i created a new sitemap and after google updated the sitemaps it is still saying that i am missing those pages. What does this mean?
Google is still looking for the old pages and will keep looking for them until they figure out they have gone. You should either do a 301 redirect from the old urls to the new ones or make sure that a 404 page appears if someone tries to access the old url. Personally I would go for the 301 redirect.
Remember that Google takes into account links from other domains to your site. So it's not enough to simply change your sitemap..