Tail Bone/Coccyx pain (Back Dimple)

Hi Guys,

I have always had a dimple on my lower back which is directly over my tail bone. I thought it was normal, but investigated it some time ago when I realised it wasn't. I've never had any discharge or anything like that. I do kickboxing and this involves a lot of sit-ups that have usually given me pain in the area. I've recently ramped up my training which has meant that I have lost quite a bit of weight in the area and it seems that the fat may have been cushioning the area before so the pain was not quite as severe. It is now much worse and means that I can't really do sit-ups using proper form and have to basically sit to one side on one of my bum cheeks instead of in the middle like everyone else seems to be able to do them. The sensation is as if my tail bone is too pronounced. I'm unsure whether this may simply be Coccydynia, but my dimple in that area makes me wonder if the symptoms may be connected in some way.

When I was younger I was much thinner and always seemed to have lower back pain, but the doctor just put it down to growing pains.

I know very little about the situation as it's only recently that it has stated to give me major hassles. Just wondering if anyone can offer any advice on what the possible solutions could be prior to a doctors visit or options available to me. Obviously sit-ups are a staple exercise of my training and it's frustrating to be in so much pain when everyone else seems to get on and do them in comfort.