The order of the routine depends on each individual according to their preferences, so I see no prob if you jelq before stretching, although masturbation is not recommended as you will fatigue your penis.
Actually most members recommend masturbating 2 hours before or 2 hours after the routine, and some even recommend avoiding masturbation in the days you do the routine as they claim it might hinder gains, although there is no real consensus on that topic yet.
Don’t worry you will get used to the stretches so your penis wont become erect anymore, it is a normal beginners problem.
Best of luck.
Was (july 07): 5.25 nbp (5.9 bp)X 4.5
July 10 :6.15 nbp (6.65 bp)X 4.8
Goal: 6.75 nbp (7.1 bp) x 5.1 Final goal : 7.25 nbp x 5.3