Dry frizz prone hair?

my hair tends to get greasy at the roots(with no help from my oily leave in products)the rest is very dry and now i have these baby hairs coming in that are frizzy. i have wavy hair, i do not, rarely ever blow dry due to the damage it causes and im trying to grow it long. its just past my shoulders and im so tempted to cut it all off because i want healthy looking smooth hair. i have not done highlights in a year or so,,any suggestions..btw, i have used everything imaginable as far as products go..kpac(did nothing special for me) redkin, and alot more..