Pregabalin (Lyrica)

Hi, I take 600mg of pregabalin a day on top of 800mg carbamazepine and 15mg of amytriptyline for trigeminal neuralgia. I am trying to reduce carbamazepine as it is reducing white blood cell count. I do not wish to reduce pregabalin as the pain is unbearable if not controlled and I only want to reduce one drug at a time. Over past year or so I have gained about 1 stone 10 pounds. I have lost 10 of this but it has taken forever. Tried slimming world, tried weight watchers, switched to calorie counting. I've tracked my food on my fitness pal for last few weeks. I've been trying to aim for 1200 a day but managing 1300 to 1400 cals a day. I am 5 feet 10 and weigh 13 stone. The last 2 weeks I have gained 1.5 pounds. This is very discouraging . I suppose it doesn't help I'm 54 and menopausal but even so. I swim once a week , go to aqua fit once or twice a week and walk dog . I can't up the exercise too much due to arthritic knee. Any advice on how to shift weight ? Many thanks 😊