I think it is best to see a doctor in order to get the right prescription for your toenail fungus, since you already mentioned that it is already in bad shape. However, if you feel that this is not an option for you, you could at least use otc to treat your toenail fungus. ZeroFungus is the only anti-fungal product I can recommend because my mom tried it and it worked well for her. Of course, try to practice good foot hygiene to prevent the fungi from spreading. I wish you luck in treating your toenail fungus.
I don't believe that you need to see a dermatologist to get cured of toe nail fungus. The best way to cure this skin infection would be to opt for any herbal and homeopathic medicine like Fungisil and Zetaclear. Both the medicines are really very effective and there are several reviews available from people who have used these health products and got well ...
Go see a dermatologist (a doctor who specializes in skin problems), and see if you can take Lamisil (pills, not an ointment). This attacks the fungus from the inside. It is a prescription medicine.