Thank you for your question. Although without being able to examine you I can not offer you the specific advice on diagnosis and treatment that you need, but I would try to provide you some relevant information about your health concern.
Usually, muscle cramps are common in salt imbalance, circulatory problems, with certain medications, excessive cold temperature, whilst you are relaxed or resting, during or after exercise, or after sitting in an uncomfortable position. Most of the times, they are not related to any underlying disorder but needs checking out with a doctor to assess that your leg circulation and nerve supply are working appropriately. Meanwhile, I would suggest eat a diet rich in fruit and vegetables, vitamin E & zinc supplement, drink at least eight glasses of water in a day and avoid smoking. Hope this helps.
From my knowledge, could be one of two things. The most probable idea is you may have a neuromuscular problem called Restless Legs Syndrome. There are organizations who have websites that explain that issue, like rls.org, and I have RLS, so that's how come I replied to you. The other idea is if you ever notice your lower back gives you problems, then it could be you have some sort of disk, bone, or swelling problem in the lumbosacral spine that is pushing on the nerves that go into your legs, and thus they seize up.
On the RLS thing, if you notice it occurs more significantly in one leg than the other, becuz with RLS it starts in one leg, then that may be what you got. It can also be a familial thing, where you have it all your life, and perhaps someone in your family lineage has had it, too. It can be mild enough early on to where you just live with it, so a family member may not have complained about it, so you need to ask your parents if they have had cramps in the legs or if someone else in the family had it. If so, this also points to RLS. There are various categories of medications that will help with it, some make it go away almost totally to where you almost forget you have it. An good internist or a neurologist should be able to determine if it's RLS or not, and they can prescribe medicine for it. I might add that the twitching you have in your eyelids and face, this can be caused by inadequate sleep. See, RLS can wake a person up in the nighttime, and thus disturb their sleep, and they'll get facial type twitches becuz they're tired without really realizing it.
On the lumbar spine thing, if you have felt discomfort in that region for a while, then it's very possible you've got a trapped nerve in there, perhaps from a disk protruding, or maybe a moderate curvature of the spine, just enough to push on the nerves, or if you are sitting in a chair all the time that doesn't support your spine very well and thus you wind up with swelling in the lower back area, that can push on a nerve. Anyway, if you've noticed discomfort in your lumbosacral spine area, you might want a neurologist to order a scan, to see how the nerves are doing there. Again, there are treatments for all of those possibilities, ranging from drugs to physical therapy, all the way to surgery.
There's a slight possibility that for some reason you really do have tight muscles, and I've heard of people having to get an operation that will release some of the tension. And even tho you may be getting enough iron and potassium and all that, the fact that quinine helped you somewhat DOES point to a lack of some mineral, could even be some glitch in the way your body processes minerals, and you might can get an iron I.V. periodically, or higher doses of whatever vitamins and minerals may be deficient, which they can determine that by drawing blood and seeing what your numbers are. Those would be my thoughts on the problems you're having.