Why is kungfu practice making me sick?

Lorazepan (generic name for Ativan) is considered having a highly addictive potential and is normally used only for short term treatment. After stopping the medication withdrawal symptoms can last 6 months or more so it would not surprise me if at least part of your troubles are still from withdrawal. Lorazepan does affect the memory so your feeling 'trapped in the head' makes sense. Being dizzy, and nausea are also symptoms of withdrawal.
How hot is it in Taiwan right now when you are training? This is another possibility. I know they don't often have air conditioning over there and most people are not used to the heat. If you train in 90 degree Fahrenheit or more weather this too can make you sick and if you are lethargic the rest of the day that would indicate heat exhaustion. In that case drink lots and lots of water before, during and after training to minimize the effects and then simply train really early in the morning or later in the day and take it easy during the hot mid day.

You need to go into detox. Good thing for you a combination of massage, acupuncture, chi gong, and lots of water will get the job done and all of it can be found in Taiwan in a short distance.

It's time to delve deep into the martial and medical community there for the masters in healing and ask their advice on how to detoxify your body of artificial chemicals. You will probably need a full set of facial massage, to realign your blood and nerve flow. Including work on your adrenal glands and organs. Plus chi gong and water to flush out all the bad stuff. Keep physical exercise to a minmum. Avoid high kicks or exertion.

The kung fu is probably stressing out your body, when your body needs to rest and detox.

8 bottles of 1 liter water a day should do it. Although most of it can be compressed into a few hours if you dislike drinking water throughout the day.