Dear @Margotsylvia
I understand your "despair" over your weight gain and your wish to remove the extra weight as quickly as possible. Whatever plan you decide on for losing weight does need to be doable for you - which includes that you don't find it too unpleasant. Of course, it may well be that your motivation to lose weight will help you stick to more strict plans. But given your health issues, I feel it is important that you do eat nutritiously and keep a wide range of whole foods in your diet, and don't put too much stress on your body through long fasting periods. Have you ever tried eating according to your hunger, choosing nutritious whole foods - as per the Amanda Salis approach?
It is possible that because the extra weight went on quite quickly, that if you return to normal eating, and reduce / remove the added sugar / non-wholegrain foods from your diet, that the weight will come off quite quickly.
Best wishes and good luck whatever you decide.