Hello there,
I see you have recently joined Med help. If the something is what you wrote in your journal entry, ie. cocaine , the answer is yes. Should you be using it .
The answer is no you shouldn't be using it. It can make you very sick.
If you overdose on cocaine, you can damage your brain permanently or die of an overdose. I know what I have told you many sound harsh, but I believe in telling the truth. Knowledge is power. In your case, the power to know that you should not be using this highly addictive and dangerous drug.
Yes you can. It can happen overnight
I'm sorry I only read your question last time. But after reading evewisewomans comment I had to dig a little deeper to understand her comment. Anyway eve wise woman is correct. Yes you can become allergic to something you enjoy at the drop of a hat.
And no you should not be using this drug at all. Its a very dangerous drug.