How to log exercise properly?

Hello,
I have a herniated disc in my back (L4/L5) and sacroilliac nerve damage down my right side which makes my right side very weak and prone to stumbling/dropping. (My left hand can press 11kg my right only 1kg)
So quick question, how do I log my exercise on the app? Even walking 10 mins has me sweating, heart pumping and planting due to the effort it takes, so surely I'm using more calories than the app telling me my slow pace for 10 mins is like less than 50 calories?
Should I double log it? Or maybe put it in as extra effort despite me walking very slowly? Some days I can barely walk so even stairs is very tough, and I've to walk in a swimming pool as per my consultant and physio orders, how do I log this? It seems simple but with the pain I live with constantly it's all double effort. (I was marathon training before my back injury and the stairs feels the same as when I hit 2km running!!)

While the app is great there doesn't seem to be any leeway when it comes to exercise, surely the app should take into account injury which may mean simple exercises take much more effort?

Thanks guys, I'm just lost here, the app telling me my 10 min walk where I felt like I ran 5k was only worth 40 calories makes me feel really down hearted.