WordPress Sitemap, Posts & Hack issue

hi, first post here, please excuse me if some of my terminology is incorrect!

Here’s what’s happened (I’m in a real pickle). Firstly, I’ve got a habit of meddling by renaming or deleting categories and tags.

Up until around mid-July, my site was doing really well and everything was ticking along nicely. Then my stats dropped heavily and I’ve spent six weeks trying to fix this.

I use a translation plugin (Transposh) that adds to the permalinks to denote the translated page (i.e. ukmobilereview.com/fr/ – ukmobilereview.com/zh/ – ukmobilereview.com/bg/ and same with post URLs). I’ve suffered from high-CPU and server resource usage for months (and have increased from a standard shared hosting to my own dedicated VPS, the highest level possible with HostGator and I still have issues).

Very foolishly I deleted the row in my table that said xx_translations (renamed the first part for security). This caused the history of all my translations to be deleted – I restored this about 24 hours later when I realised my issue. However, my readership has dropped by around 80-90% since before the drop in stats in July.

Some of my other changes include switching to WordPress SEO by Yoast (instead of All-In-One SEO) and implementing Jetpack by WordPress to provide a secondary set of stats.

I’ve resubmitted numerous sitemaps to Google (using XML Sitemap Generator) but the volume of readers is still really low. In real terms, we’re talking about the fact I’ve lost the readership built up in the last 8-9 months, which is a really tough pill to swallow.

I’ve also looked at Webmaster Tools who says Google has found around 33,000 404 errors but I’ve tried to manually fix each one using a 301 redirect in my .htaccess as well as run Broken Link Checker yet the figure still remains extremely high. (A lot of these point back months and months).

I’ve got one option left which is to export content using WordPress exporter or using PHPMyAdmin and then hit the reset switch by deleting everything and starting over. This is quite a long task but I’d be interested to see if anyone has any thoughts on this?

Now I’m not averse to changing domains but this would really have to be a massive last resort (due to the fact I really really like my current domain and it has worked wonders for me business-wise).

The site URL is http://www.ukmobilereview.com and with some new features and functionality we’re currently planning to roll out, I desperately need to get this fixed.

Can anyone make any suggestions (this would be REALLY appreciated) or point me in the direction of someone (free/paid) who could help resolve this once and for all?

Thanks in advance, it is REALLY appreciated!