Hi Leyla, good to talk to you.
It sounds a little bit like you may have some spinal kyphosis, which is outward curvature of the upper back, particularly the cervical vertebrae.
Have you had any consultations with a professional of some sort, like an orthopedic specialist or a chiropractor, as you might need some kind of consultation.
You might want to do some research into something called the Alexander technique as well.
Giving you a back workout may worsen things, especially as someone strengthening their back without any strengthening of the chest area, could cause muscle imbalances, that could affect spinal posture and lead to pain, discomfort and potential impediments to bio-mechanical movement.
I can't ascertain from your description of things, if you somehow have a muscle imbalance, some kind of onset of a spinal irregularity, or some sort of other medical issue, so it wouldn't be right of me to suggest weight bearing exercises for the torso, because your description of things, doesn't really identify what the underlying cause of what your problem might be and that's not your fault, so I hope you don't think I was criticising

.
Hopefully everything I've said makes sense, but I will still ask if you've had any consultations with a professional about this and if so what outcome(s) arose from it?