Chimera ( as in the Greek fire breathing monster, surely not an illusion because I see @ICK in those pictures? ), Welcome.
Number one and foremost; I cannot emphasize it enough. Keep your diabetes well maintained. I've taken care of diabetics before and poor blood circulation is a common problem, especially when proper control is not taken. Diet and weight loss can sometimes make a diabetic no-longer diabetic, but damage caused by diabetes is seldom repaired. Keeping proper blood flow to your penis is an important part of penile health.
2. Cut tight is not uncommon. It sucks. I was cut so tight that when I was an adolescent the erections would cause tears in my skin. I asked my dad about it and he said it was 'because doctors take of a lot of skin when they circumcise, don't worry about it, everyone gets torn skin but it heals'. What a load of $#it for anyone. Later on, i heard nurses used to beg other doctors to not let a drunken old gynocologist here circumcise infants because he always took off every bit of skin he could pull up. A friend of mine told me a hairy shaft is not pretty when it has to pull ball sack hair up to cover it. I shaved mine for years, now just wax it. My skin used to get so tight it would bend my penis when hard till I was about 21-22 years old. Female genital mutilation is illegal but male mutilation still everyday practice in the U.S. From that standpoint, I feel for you buddy.
3. Foreskin restoration is possible. I never was able to grow much but have a friend very well restored. I was on foreskin restoration sites in the 80's and it appears the younger you are, the faster and more successful you are at it. Now he is working on overhang using an inflatable device. I can tell you that when I was working at trying to restore, my covered glans was very sensitive and sensual. I keep thinking about putting some effort into it again. There are web sites for restoration. N.O.R.M. can give you directions. P.M. me for any questions if you are trying a method. Devices can be bought on eBay for $40. Use foreskin restoration in the search box. 30 years ago, we made our own. I made spring loaded ones and all kinds of gadgets.
You are the second person recently that I have seen using that style extender. It is cool. The suspensory ligament is on the top side of the shaft so I would hypothesize that you have a better than average chance of working through the bend with your tension than the person who bends up. Other than the curve, it looks like you have a nice young healthy looking penis yet. Often tough areas, and lumps can be felt with peyronies. Here is a question: When you are erect, can you manually bend it straight without much effort? I am not suggesting to try to forcefully bend it straight. That may not be a good idea. I would suggest if you sleep on your stomach to point your penis straight up toward your navel when you do. That may give you a bit of free bonus help. I definitely would not sleep in briefs with it pointed down as that will not train it the way you want it to go or help when you have nocturnal woodies. Cheers man.