Good, strong, excellent, and proven advice above from everyone.

Two big things interfere with our sense of balance and our ability to keep ourselves erect: medication (too often polypharmacy) and sarcopenia. The first is rather clear, if unfortunate, and the second (muscle loss) is just a fact of life, aged life.
Quick turns, in loose fitting slippers that drag on the floor, or that catch on throw rugs, are often what causes falls. Failing vestibular systems (inner ear). Not lifting one's feet off the floor, and shuffling, often from a fear of falling.
Building muscle and muscle tone is important. Too many fail to do it. If you already have trouble getting into, but especially out of, a chair, then you should seriously consider fixing that. It can be done, it might not be pretty or fun, but inside of a month you might be surprised at how capable you are if you do exercises daily.
Balance exercises (see YouTube videos under a search for 'Balance exercises for seniors'). Or try a search for, 'preventing falls in seniors'. Then............................................DO THEM!!! At least three times each week. Forever.
If you could live without some of the medications you've been prescribed, it might help...a lot! By now, you probably need one or two to live well enough to keep living, or to want to. But some of them you might find you can drop, safely, with consultation, especially if modifying your lifestyle takes up a lot of what they do for you. I'm not suggesting you ARE taking unnecessary medicine. I'm suggesting that you may want to experiment, with a physician's support and agreement, to try to wean yourself off one of them, maybe two or three. It's worth a shot.