is there permanent treatment for premature finishing?

You might want to try edging – masturbating until almost ejaculating; stopping and letting the urge to ejaculate subside a bit; then repeating the process over and over, keeping from ejaculating for as long as you can. Doing this daily (or several times a day) for a couple of weeks often helps a man to learn to control his ejaculations during partner sex.  On a separate note, keep your penis healthy with the regular use of a premium penis health cream (health professionals recommend Man1 Man Oil). A cream with alpha lipoic acid can help to prevent penile cell aging.