salvage my efforts or uninstall? – missing post/missing formatting in admin

I am real newbie to WP and to anything related to using a database on a server or php. I had quite a feeling of accomplishment setting up my site, which was not so bad. After 3 longs days of work to get WP up and running and customizing a template to my liking and entering content, I changed WP address (URL) then lost the site (the 404 message). I jumped the gun and after I read on this post about how to fix, I logged into my host admin (called websiteOS) and foolishly used the “Database Manager” in the WebSite management to try to complete the same task. I assumed it was the tool that was my equivalent to phpMyAdmin and since I set up the database with it I could use it for this task as well. I was in such a hurry to correct my fatal error that I did not notice I DO have phpMyAdmin. SO, I ‘updated’ a table (or a column??) as follows:`Query: Update wp_options Set option_name=’siteurl’
OK completed successfully
109 row(s) affected `

Next I got on chat with tech support and they tried to restore the database to the state it was at their last backup. So, I used phpMyAdmin to fix my URL, the site loads, but I lost several posts and a page, and the css seems to be missing from my wp-admin.
I know I shouldn’t have tinkered under the hood..
All that to ask if I’m best off to delete the entire WP software and database from my server and start over (after backing up all the tweaks I made to my template’s css), or try to fix the formatting issues with WP admin. ALSO, is there a way to get my missing posts back? The media files (images) that I uploaded as part of the now missing posts are still in the wp-content folder. I feel like I screwed up and there could be other things not correct. I’m at wit’s end! …