You should probably avoid this exercise then. Or try to bend it in the opposite direction (upwards)
Things that help fix curves: [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]Extenders[/words]
Manual stretches
Hanging
Regular Jelqs
It's best to work length before girth anyways. I strongly suggest you do this. You can do jelqing as well but stay away from the heavy girth exercises until you reach your desired length - unless for some reason you are completely unhappy with your girth, then you can do a bit of girth work to make it larger girthwise.
I suggest that you do manual stretching until you plateau from it (go 1-2 months with no BPFSL gains) then move onto
hanging. So that would be anywhere from 3-6 months of manual stretching, then
hanging anywhere from 6 months - 2 years.
I also suggest that you get an [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]extender[/words] and wear it as often as you can - especially since you have a curve you wish to straighten. It would be the easiest way to do so - it will maximize your success straightening in the time you practice Penis Enlargement.
You should be jelqing no matter what routine you are doing - always jelq. Light jelqing is best - not extreme force jelqing.
Hanging will also help greatly with fixing a curve, just the nature of the exercise alone.
Then, once you are finally ready to work girth again, your penis should be relatively straighter than it is now and you will be able to do any exercise you wish.
So since you wish to straighten your penis, I strongly suggest working length first - then girth. Manual stretching then
hanging. Jelqing all the while. Wear an [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]extender[/words] all the while. Lots of guys don't choose to do it like this but I believe everyone should just because of the logic behind it. And since you want to straighten your curve, it's just natural that you should do it this way.
If you don't believe me, read up on threads about
hanging at pegym forum and bibhanger's forum. You can check my progress thread too. I am taking this approach. Hopefully it will serve me well - I think it will.
Good luck.