i am determined on getting 0.4 inch length in the summer vacation.

That's why i go from 15 min to 20 minutes of stretching and of course 20 minutes of jelqing (=

Well my guestion is, should i warm up again after the stretching part, seems like my penis get's a little cold after all the stretching.

It's about a month and a half left, is it even possible, it's 1.3 cm

Maybe i should add in more stretching time ?