Manual stretch grip

Hey everyone, I was wondering if anyone had any suggestions for my manual stretch grip. I’ve dabbled in PE before, but haven’t been able to find a good way to stretch where I feel safe about it (having some minor spots appear occasionally). I just want to do things right. I’m uncut, and when I do my stretches, I find that even with adjusting my grip several different ways, I still end up with my glans being very swollen mid-pull. However, unless I pull at a certain force, I don’t really feel like I am getting a good stretch. Can anyone ascertain something I’m doing wrong, or could just be that I never really attained a good conditioning level for PE (I did it for around 1 1/2 - 2 months, with breaks when marks appeared)?