I’ve been dealing with something similar (although there’s no way to say specifically if it’s the same, so please understand it could be a different injury).
In PE there is a technique called manual clamping. It’d be similar to squeezing tightly as you describe, although to what degree and intensity would differ. What I did was a short manual clamp but as I was kegelimg blood in I think I moved my hand up slightly. The combined effect was that, I think, too much pressure was put on the glans, whether the end if the dorsal vein or the smaller veins and capillaries that go into the head I don’t know. Maybe both. Maybe the pressure affected the nerves there, though I’m not sure about that.
The thing was I felt a stinging pain and immediately stopped where I believe you didn’t notice anything until later. Also I have no pain at the base or red marks. I did get a sore urethra and burning/soreness in the glans, aggravated by erection or “use” (which I only did after a week very lightly.) Still it was a similar force applied I think as far as technique is concerned, though maybe not degree of force (I wasn’t squeezing with all my might or anything.)
What guessing (that’s all it is) happened might take awhile to heal depending on the severity. You say you are able to achieve an erection, so that’s good. The pipes are working. I do believe penis injuries take a long time to heal. To aid it, consider taking fish oil high in DHA (look at labdoor.com for the best quality, it matters), kyolic aged garlic(the advanced one for circulatory health), vitamin d3, vitamin c, tumeric(curcumin )and possibly something like osteobiflex (glucosamine, msm, frankincense).
Basically you want to avoid chronic inflammation while allowing beneficially inflammation. Sounds weird but acute inflammation is good and a sign of healing. Chromic inflammation is bad and gets in the way of healing.
Eat healthy, get sleep, quit over analyzing your penis (I mean don’t ignore obvious major issues like rash or fungal infection , which are not always tested for in STD screenings, like yeast infection that guys can get…or bleeding or something major)
My penis head is sore too but seems to be healing. I ordered a few things off amazon. Helichrysum oil (it’s expensive so if you decide to buy beware, lots of fakes, I trust plant therapy brand), st johns wart oil, some aloe vera gel, and some comfrey oil. All just to ward off excess inflammation. Warning: anything you apply to your penis should be tested on your arm first. Then a tiny amount of the base of your penis. Then a bit more. Point being, don’t irritate your dick. If you have a bad reaction it’s better to have on on your arm right?
Keep us posted. Honestly sounds like youre healing slowly. Just don’t reinjure by being rough with it.