What is the best way to deal with ragweed allergy, if you don't go to a doctor?

Meds/sprays. A simple non sedating once daily antihistamine like loritadine or fexofenadine can help many. Some people have better response to one med than the other. An over the counter nasal steroid can also help. Nasal steroids often require a week of use before you see noticeable improvement.
Allergic rhinitis. Otc antihistamines usually help control your allergy symptoms. If not, prescription nasal antihistamines and steroids will also work. Otc nasal sprays are usually indicated to unclog the nose. Caution should be exercised when using neosynephrine as its chronic use will only worsen nasal congestion.