I'm afraid I have adhd, but can't afford to go to the doctor. Do I have any other options?

Many. Make sure to get a good nite's sleep and keep a regular schedule. Avoid junk/refined foods and eat organic food as much as possible. Start both a good quality whole food multi-vitamin/mineral and a fish oil supplement. Start on an exercise program. Avoid stimulants.
Nutrition. I assume you mean what can you do without a prescription. There is evidence for omega-3 fatty acid (a.K.A. Fish oil) supplementation, zinc replacement, and iron replacement all providing benefit for adhd symptoms. Time spent in nature and adequate sleep have also been shown to reduce adhd symptoms. In summary: good nutrition, fish oil, a multivitamin, good sleep hygiene, and time in nature.