Hi Bernice,
It sounds like you had some major breakage from the perm. The reason why the ends are still thin, is because 6 months ago that hair was near the scalp or mid strand and the perm burnt it, so it is breaking off. If the hair was damaged enough from the perm it will take having all the hair that was permed trimmed off in order to get rid of the breakage. There aren't any products that repair hair damaged enough to cause breakage. Sometimes the breakage from a perm is not even from being overprocessed, at least half of perm breakage is from a bad wrap. The perm rods where wrapped up too tightly, or with uneven tension. The hair swells slightly during processing, and if the rod is too tight or pulling the band from the rod "crimps" the strand and caused a weak spot that will break.
Keep in mind that a perm does not effect the follicle. Your new hair will grow back healthy. The only way a perm will effect the new growth would be to get a chemical burn on your scalp that damaged the follicle.
About your having your hair thinned, most hair stylists thin the hair with thinning shears, again just a method of cutting. So in 4 yrs unless your hair is not growing or your follicles were damaged by some sort of trauma, the thinning by your stylist should not still be effecting you now.
My advise would be to keep getting regular trims, and use a good shampo oand cond. for chemically treated hair. Check your brushes and picks, if they are old and worn out that could be adding to the problem. Plastic can get little jagged edges to it over time, and will grab the hair and break it too.
Hang in there...I am a hair dresser and have been through some amazing hair horrors too. But hair does grow back <IMG SRC="http://www.healthboards.com/ubb/smile.gif">
Tonja
