I'm early 30s and 3 stone overweight and pretty unfit. I've lost 1 stone with SW and will keep going with this. I do a fair amount of walking (live in London so walking to and from the tube etc), around 9k steps a day, but this is generally on flat pavement. Anything more strenuous or involving walking up a hill or steps gets me out of breath. I suffer from lower back pain and I'm sure having a stronger core could help with that. I went away to the countryside with DP recently and did a lovely scenic walk but felt like my chest was going to explode. I often feel exhausted and sluggish and I'm sure getting fitter could help with that, though it's a vicious circle as I feel too tired to exercise.
Does anyone have any suggestions as to what's best to get fitter and stronger, have more energy and find life a bit less of a struggle? Preferably outside of gym membership as cost is a factor. Any inspiration or success stories welcome, as well as motivation tips.