Adding stretches after 2 months?

Hey guys I was wondering if I could add some stretches to my beginner program. I'm following JP's 90 day program. It has been 2 months was thinking about adding Side to Side stretches as well as what I've been doing. I'd do a thousand of them. The jelq free program is the program I was going to do next. I got the Side to Side stretches from this program, so I figured why not start a little early? I'm getting tired of doing the same exercises and would like to switch it up. I workout a lot and if there is anything I've learned about being in the gym is that you need to switch it up or else your muscles will adapt and not grow. Is it the same thing with my penis? I believe I'm beginning to see slight girth gains from following JP's 90 day program. I started with 6.2 girth now 6.3 girth. I could really use some length I'm 7 inches long and gained no length yet. I'm aware I still have a whole month left and could see gains within that time. I'm a very hard worker and will do these exercises for as long as it takes to get to 8 inches. I'm a nube here so please help. I'm 18 years old btw if that's important.