Have you tried caffeine or energy drinks?

This does NOT work for ADHD and is a TERRIBLE idea

Research does show that nicotine can function as an effective treatment for ADHD. In fact, researchers even tried to remove the addictive part of the nicotine molecule specifically to be able to use it as a treatment for ADHD, but removing that part made it not work.

Best bet is to use the patches so you don't develop an associated physical or sensory habit

It can help for me, but it certainly doesn’t fix anything

There's so many things to get hooked to other than cigarettes. Or maybe not so many, but for me at least that's nice food, sometimes sugar, coffee, tea that I like or any other activity not related to ingesting something, maybe writing, reading, whatever. I feel like this kind of addiction is not worth it however beneficial it might seem at first

Many have been there: How much damage in life is happening between suspecting it's ADHD and receiving treatment.

What I found most effective is Modafinil, if you happen to live in a place where it's considered a lower schedule prescription drug and is easily accessible. It's less safe, so follow doctor's orders and instructions carefully. Use 1/8th of a pill to check tolerance on day 1.

If you have not built tolerance to caffeine, that is effective for a couple of months as well. Consider guaraná or black tea if you need a lasting effect for many hours.

Another option is if you ever got a prescription of an anti-depressant that works off-label for ADHD as well and have some left over. Many of them take a month to work, but sometimes, the ADHD effect is immediate.

Of course, when you get your real prescription, check if you need to stop the temporary one first! In case of some anti depressants, that can be several days.