Help required

[PG0078]

Hi I am 40 year old and was around 260 pounds at the start of April 18 and now currently at 220 lbs. I mainly started gymming and diet control at the beginning. I had a huge gain in terms of loss in the first 4 months and then reached plateau and also started skipping the exercise and eating habits went array. Still didnt gain much and maintained more or less 220 lbs + - 5lbs. Start of december I again started training with a focused goal of reaching 200 lbs by March 2019. This time around I included C25K in my training including gym. My goal is to run a 5K by February under 40 mins. From the start my instructors havw discouraged me to take up running and cardio and asked to concentrate on weight training. Now again they are asking me to do the same but this time around I was determine to try. I am on the 3rd week of C25K programme and have not faced any issues and infact feel better expect for soreness on some days. I train in gym for 5 days a week with additional 4 days of running(C25K) included with my gym workout (included mostly of body weight training). I need to know whether I can follow the same routine or is it too much. I am feeling ok but fear a burn out or over training. So need guidance to balance my gym work out with running. The gym instructors are dissuading me to discontinue with the running as it would lead to knee injury and doesnot assist in weight loss. Can someone guide and help . thanks