After some helpful threads about this, I tracked my meals with Myfitnesspal AND WW. This made me realise I should reduce my WW points to 25 a day and NOT use my weeklies, except on Mother's Day. 
25 points a day keeps me more or less at 1200 calories a day so I know I'm not eating too little and putting my body into starvation mode. So after approx 9 weeks of losing nothing and sometimes putting on a lb or 2, I've finally started losing again and have lost 2 lb in the last week.
Over 3 months on this stupid plan and only just reached a 7 lb loss!! I now have 14 lbs to go.