Newbie and help

Hey all, new to this, I've been over weight for 16 odd years. I'm 37 years old. Booked 1st family holiday to Bulgaria next June and didn't want to be the white whale at the swimming pool. I started cutting down and started C25K. Finished the C25K and got time down to 26mins,(live the 5k) moved onto 10k and done it twice at 56mins but picked up a slight niggle. Was going to a pt once a week. Now joined a gym, running 5k 3 times a week and 3 morning cardio classes. (boxercise, trx & circuits). In August I was 17st 9 and now down to 14st 3 (depending on time of day) I feel so much better and loving my new life routine. Here's the 'but' I just can't seem to get this last layer (large one) of belly fat and love handles off. I'm working really hard at my core but just doesn't seem to be working