I suspect that the peeling removal (vs soaking off with acetone) may bey why you're experiencing more weakness & dryness. Peeling off the gel also removes the top layer of your nail. I know the shields *say* you can peel them off, but it makes sense to me it would also remove a layer of nail at the same time, since they're attaching with adhesive, and especially if you're having to pick at it to get it off.
I don't use the shields, but what I do is soak mine off with the foil-wrap method, then I massage in a heavy-duty hand & nail cream. Sometimes I'll even dab a good-sized "blob" of it onto my nail beds & cuticles, and let it sit & soak in for 10-15 minutes before I work it in. I then wait & redo my next manicure the following day. You might try adding some extra moisture between manis.