@Roxy there are very good chairs out there for sitting. I have been pretty much sedentary for most of my life with a heavy fascination for computers, so chairs are pretty high on my list of things that need to work for me. Before I dropped a ton of weight (I was 225) handling my weight without breaking or deforming a chair was a priority. I currently use a gaming chair from a company DSX Racer. It is really nice because it promotes good posture and allows me to sit on my lazy ass all day. The company that made this chair used to design chairs for the racing industry and you can tell by the way the chair is built. Think bucket seats in a really nice car.This might be something that could help you too.