I was on antibiotics for 12 days as of the 26 of nov and last week my started to get itchy and their was a white ( wet toilet paper ) looking stuff this week it's not as itchy the white stuff is still there but now my vagina is itchy around I know that's a yeast infection so I started using cream for it yesterday and still not getting any relieve. Also as of yesterday I get dizzy and nausea what's going on?

Ideally our bodies supposed to have a perfect balance between so-called "good" bacteria and "bad" bacteria. Candida (yeast) is one of the many forms of bad bacteria. Some people (many actually) have candida overgrowth and as a result get yeast infections. This could be anything from athlete's foot to jock itch to vaginal infection (although the last one also could be sexually transmitted). Antibiotics is a mixed blessing but more of a curse now. Because of uncontrolled antibiotic use the bacteria mutated and became resistant. As a result we need higher doses of antibiotics, but still many bacteria don't respond as well as 20 years ago. Additional huge downside of antibiotics is - when you take them in high doses for a week or so you kill a great number of good bacteria. As a result you create a huge imbalance in favor of candida and many other harmful bacteria. OK, enough science, what is the solution?
There is a short term and long term solution. If your yeast does not respond to your creams and whatever else you use, consider visiting a doctor. Go to immunologist rather than to a general physician because severe cases of candida indicate a weakened immune system. Long term solution - help your body to get more useful bacteria. Eat yogurt with active cultures every day. Active cultures in yogurt are probiotics (good bacteria). Take probiotic supplements.
You may try also pre-biotics. These are natural fibers and enzymes that help to form useful bacteria. The easiest and cheapest way of getting prebiotics is getting chicory powder, you can find it online. Get ibrik (a turkish coffe maker). Fill half of ibrik with water, drop half a teaspoon of chicory in water and boil like coffee. Add sugar to taste. You may also add a pinch of coriander, vanilla extract and cardamom if you want. Let it sit for a couple of minutes. Meantime brew your favorite brand of regular coffee or decaff, or you may use even instant, does not matter. Then mix chicory and coffee 1:1. Milk to taste if you want. You will get a delicious drink that goes well with chocolate, pastries, regular sandwitch or solo. And it will form good bacteria in your body. Homeopathic doctors also can help. They use Epsom salt baths for candida and usually have significant percentage of success.

There's no way to diagnose on the internet. If this is a concern then you need to see your doctor.