Just give it time. Say 3 months, rather than six weeks.
For what it is worth, most pumping vets say 5HG is the max pressure you would want to go. I had the best results with 3.5 to 4.
For example, see this post by gprent:
Originally Posted by gprent
I have been staying in the 3”hg range for quite a while now and my results are the best ever. Seems I really wasted a lot of time, like years, trying to make pumping at high pressure work. If you want to skip all the hassle and go right to getting consistent excellent results, just try pumping at low pressure for a week. I do three 12 to 15 minute sets every work out with a massage to full erection between each set. Finish off your routine with a full erection for at least 5 minutes. You will be impressed with you flaccid size and EQ.
gprent - Soft when I exit pump
That’s a pretty good workout by the way…