This is a problematic trade off for adults. Because of the height and weight involved, trainers usually hace to be set for full time ground contacr, holding the bike rigidly vertical. As such it rides more like a trike than a bike, except it's much more tippy.
A single trainer won't help, because it affords to anti-tip protection in the other direction. Plus if it's set to allow you the normal side tilting of a bike it won't bd reliable to keep you from falling.
It's hard to advise without knowing the details of your condition. Balacing a bike is s learned process involving the cerebellum which uses steering inputs to keep the bike under you. It's the same functional pathways you use for walking, and just about all your motion controls.
So, if you have no brain injury, odds are you'll improve over z short time frame.
OTOH, if you do have a brain injury affecting motion control, usually such that you walk like a drunk, then you'll have comparable issues riding, and may have to limit yourself to MUPs, and speeds where you aren't likely to get injured in a fall.
Or consider z trike, or recumbent trike.
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