The description of your nails fits that of brittle nail syndrome. Nails in this condition tend to be thin, peel, chip, and crack, as yours do. In addition, they fail to grow to a significant length. This is due to dehydration of the mill plate and is much like having “dry skin of the nails.” Wearing gloves is an excellent idea, as is taking a multi-vitamin with minerals. A good biotin supplement may be helpful. Also, it is advisable to keep your mills well-moisturized.
There are many causes of brittle nail syndrome, particularly if your nail beds hurt and are red. You ought to consider that it might be an allergic reaction to a nail product. I would not recommend the use of acrylics because this can surely aggravate the problem. The lifting up of the nail plates from the nail bed could be due to excess moisture accumulation or an allergic reaction.
I do not believe a direct link exists with your back problem, although a few medical disorders may result in brittle nails, such as an underactive thyroid, for example. A careful evaluation of your general health would be a very good idea.
Some medications do affect the nails. Since you are on several, this is something for you to look into with the doctor prescribing than.