I was on medication when I was younger but now I use supplements along with behavior modification, meditation etc etc. My favorite supplement is beCalmd, its expensive though, so since you have issues with money that probably isnt the supplement for you

I was taking beCalmd and it was more effective than any medication I had taken for my ADHD. (diagnosed with "SEVERE ADHD/ODD") Now for the purpose of saving money I buy my supplements in bulk (3months supply) One ingrediant supplements, then I just measure out the amount of each supplement so that it equals 3 beCalmd caps.
A very cheap supplement that has a "stimulant" like effect is L-Tyrosine. You can buy this in your grocery store, about $10 for 2months worth.
D/L-Phenylalanine is also good for some people and its pretty inexpensive.
Omega3 is important.