Ok, if you are not stretching its probably a good idea to stretch.
With a LOT of eight, probably the easiest gains to go for are lig gains. Jelqing upwards will be hitting your tunica a lot but not the ligs.
Add 10-20 minutes of stretching in a downward direction, below your LOT. I’d suggest the BTC or straight down would be best. BTC are easier in a standing position but straight down you should be able to manage sitting on the edge of a chair. Try to stretch with a straight arm if possible so that you can hold a stretch effectively.
It sounds like your jelqing is having good effect but even so I would consider cutting back. I think a lot of people jelq for extended periods when they can do the same work in 15-20 minutes (excluding warmup). Try to jelq overhand in a downward direction or a lower level some of the time, this will turn your jelqing session into a lig pulling exercise too. If you can end strokes in a small stretch too this will also help.
If the head is ballooning way beyond the shaft size are you allowing the erection to subside too much before correcting it? A three second stroke is good and if you are starting the stroke as close to the body as possible you’re doing everything right. If you finish stroke with a slight stretch you can also gain more penis to jelq with because the penis is pulled out when you attach the second had at the base. Its also worth experimenting with the rotation of your grip, to see what works and what doesn’t and to work the whole shaft more evenly.
AndreasF gave some good advice. Gains will often not show on the ruler immediately, sometimes you may even lose a bit prior to gaining. It tends to be a process of steps rather than a continuous curve and if you are measuring frequently its easy to become disenchanted.
If another month goes by and you see no results its probably worth considering adding some intense stretching and maybe even some tentative squeezes but don’t worry about that now. At this stage if you are taking care to avoid injury whilst working hard that is the best bet, you’re penis probably has a lot of conditioning to do yet.