It sounds like it will be very nice for you to rediscover it after what you described. (And I'm sorry to hear about those events.)
For some reason, barre chords always came very naturally to me, whereas other things, like finger-picking and sight-reading, did not and were (and remain, lol) far more challenging. But the idea behind barre chords is, as you may already know, to get your first finger as close to the fret as possible without touching it, while stretching the finger across the strings involved. The YouTube suggestions above are great; I would also start practicing with barres starting on the A string instead of the low E as you'll have one less string to worry about. (You can mute the low E without really even trying to do so, or alternatively you can let it ring - a lot of chord voicings can benefit from an open E at the low end.) As you get more comfortable, incorporate the low E string. I'll assume you're a righty - you can strengthen your fretting/left hand with a number of cool doodads that are generically called "grippers" but are usually sold under some similar name like "grip master" or "the grip" and so forth. They work for non-fretting/right hand strengthening as well. (And if you're a southpaw, the gripper products aren't handedness-dependent and will work equally well.) Finally, start slow, but as you build up strength and speed, occasionally see if you can arpeggiate the notes you're supposed to be playing in the barre to see if they all ring out. If some are muted as you get back into things, that will help you identify which parts of your hand may need to get stronger. I find that so much of playing guitar (as opposed to some other instruments including piano) is feel rather than strict technique - you'll get back into the groove right quick, I suspect.
I hope some of that helps. Best of luck!!!
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