Black lines in thick yellow/brown toenail

I know exactly what your talking i have the same problem with that same nail i dnt understand what is? my toenail is real weak too!

My doctor or the ladies at the salon knew what it was. After speaking to a Pharmasist.I am currently using Daktarin 2% cream for a couple of months. It is slowly penetrating it....., watch this space

Try using Vics VapoRub. Put some on the base of the nail, and if you can, underneath the nail where it grows out from each side. Keep applying 2-3 times daily, and as your toenail grows out, the thick and yellow should diminish. Mind you, this may take 3 months, but, you should start noticing something better within a couple weeks or so.

The only other thing? Do a soak in a mild bleach solution.

this is a fungus- there are several of them. Use Loceral enamel - Daktarin is a good fungaside but this will coat your nail and prevent it from speading. Keep it dry and replace all your shoes and socks- they will carry the fungus. If it is warm weather expose you toes to the air.
The Loceral enamel will act like a fingernail polish- just paint your nail once a week after you shower. It takes a full year for your nail to grow out but will improve in appearance in about three months. If you are concerned that it will spread or is spreading then do it more often. Read the directions. Here in Australia it costs about $100 for a bottle. It will last you for all of the year so it is worth the expense. You do not have to soak it or use another product. My dad used to soak his feet in bleach- ugh- and that will irritate the skin. I was also told that it is easy to get a bone infection from ingrown nails so I don't reccommend mucking around with it other than what they say to do on the bottle- good luck, ps mine looks great after about 4-5 months