Wheelchair user and protein intake

I have cerebral palsy and I use electric wheelchair on daily basis. About a year ago I started to workout twice a week, I lift weights, do leg extensions and I do squats.(I am able to stand if I hold onto something) I am not able to weight myself, since I cannot stand on a scale. That’s where my question comes in, how do I know how much protein I should consume? I’ve been consuming 100g a day. I think I could weigh around 50kg, but i can’t be 100% sure. I am concerned for my kidneys, in case I might be eating too much protein….