How to keep up?

We have a website in 7 languanges. In may we added the 7th language but made a mistake with imports of products and we had all the products double. We deleted the dublicates, so we thought. We accidently deleted half of the original links. Our traffic has dropped a lot since then. We currently have gained someback, but it keeps going up and down. For the last 3 months i'm doing all the things on my own, like keeping the website up to date, orderpacking, customer support and all that kind of stuff. How can do you keep the website SEO updated in a short time period? We still need to update a lot of productpages because they still have the same text our supplier has.