What you need is not a diet but a different attitude to how you eat. If your current eatting pattern leads to weight gain you need to accept that this has got to be ditched completely and replaced by a better balanced eating pattern that you enjoy.
I assume you know what a healthy diet is, more fruit and veg, less fat, sugar and processed foods. Plan an eating pattern you enjoy around these basics. there are lots of recipes around us all the time, online, in magazines and newspapers, collect ones that appeal to you and try them out. It is surprising how quickly you build up a personal recipe database.
Just doing that and following it may well see weight loss. Then become more active. It doesn't have to mean going to a leisure centre or sports club. DH is starting his exercise plan by walking to the shop to buy his papers instead of taking the car. He may then lengthen his walk and just gradually become more active in the house and garden. There are plenty of exercise program online. My local village hall has regular Tai Chi classes, gentle exercises that are much better for you than their gentleness implies.
Once you have developed a new eating pattern you enjoy with a regular exercise pattern you enjoy, then you can think of cutting portions and doing a little more exercise to get your weight to where you want it and then gradually , when you reach the new weight, start eating more, possibly exercising a little less until food and weight both stabilise.