Hi Jet.
Firstly my condolences on the loss of your son. It is something no parent should ever have to endure and I am not surprised that you dont know whether or not you want to be dieting or not. You are grieving.
It might be a good thing for you to do, give you something positive to focus on and work towards, but I think it is very important that you do allow yourself a bit of slack for the fact that you are grieving and that anyone in your situation would feel like their world had been turned on its head and was being repeatedly thrown against a large brick wall.
If you think it would help you to start recovering by doing this, then do it, but only because you want to. Whatever weight you have put back on you can easily lose when you are in a stronger frame of mind, and will find it much easier to do so because you are in a stronger frame of mind.
So if you do intend to start losing a bit of weight, ease yourself into it gently, and dont give yourself a hard time if it doesnt always go to plan. I dont know much about weight watchers, unfortunately, because I do Slimming World, but from what I do know, Slimming World *might* be a better option for you at the moment because of the flexibility it offers.
Only you will know when you are ready to begin this process. Many people turn to food for comfort after such a tragedy, but we all know deep down that no matter what we stuff into what feels like an endless gaping chasm of pain, it will never be filled by the food. The only thing that can begin to help you recover, is grieving when you need to, the passage of time, and little positive steps towards the future.
I wish you well whatever path you choose, but choose it when you are ready, and not before.
(((hugs)))