Am watching...and learning. I'm the same, OP. Menopause, stress, caring for my disabled son, divorce (and now, happily remarried) has wrought indescribable changes on my Ms Average height/weight/shape.
I'd say, you ought to maybe focus on one thing at once. Eating better maybe? More water? Some daily exercise. Nothing could have prepared me for the changes involved in "the change". I believed it all to be self-indulgent codswallop. Not so!
Be kind to yourself. As others have said, there will be something you still like about yourself physically so, focus on that. I've had to accept that jeans are OVER for me. I never looked great in them but now, I look shocking. Aww, bless you OP....dieting for 50 yrs +. Wave goodbye to THAT, girl! I do think that, there comes a point when you have to stop. Just stop with the restriction and try everything in moderation.
Oh, and as for the bras.... do you remember God Wan and his obsession with hiking up middle aged breasts? 😄 He was right. A well fitting bra will give you your waist back and some self confidence.
Will keep checking on you to see how you're doing, love.