>that totally destroys my stats
I don't understand what you mean. There are only 2 stats that are mostly significant. The first is, when first learning the card, if you hit again too many times the card becomes a leech - as in it leeches your time, at which point you should temporarily suspend that card and to the others first.
The other one is the recall rate: after you learn a card (on default settings, when you hit the 1 day mark for that card) how often you don't fail to recall the information. This rate is the single most important metric in your stats, and a value that is constantly below 90% means you should probably tweak your settings to show cards more often. This can be easily done by reducing the interval modifier. A value close to 100% might also be slightly problematic depending on what you want, because you might be wasting time with unnecessary reviews, which can be solved by slightly increasing the said interval modifier.
As for your main question, you can do it however you see fit. Some people might prefer to do everything in Anki, while others might prefer to read a textbook, watch lectures etc. first and then move on to Anki for that specific topic. Don't use Anki as a way to quiz yourself, it is not a testing tool. If you want to test yourself, use question banks. Use Anki as a tool that will help you memorize things. For this, you have to do your reviews on time, or the algorithm just won't work.
