It is going to be a very long, and very painful process and your SI will almost certainly kick in. If you choose not to eat or drink, and you are not active, you'll probably live for three to five days (with water it's gonna be up to a month possibly longer), and you will feel a lot of pain and discomfort around day 2 if you continue not to drink water or eat. Chances are that unless you wander out into the wilderness or some desert someone will find you as one symptom is delirium which could make you wander around outside without you knowing it where someone could see you. Even if you decide to go to some remote wilderness, let's say you manage to get weak enough to no longer move, chances are you'll be eaten alive by scavengers. I doubt that's what you want. I'm really sorry that you feel so terrible that starvation feels like it is the only way out but this isn't a good idea.