Happy I'm the same, I think my idea of "normal" eating has warped over the years into something Henry VIII would agree with 
Welcome Mali! Cold turkey is one way to do it. It might take a bit of trial and error to work out what works for you. I would personally take it more gradually. Start with either crisps or booze as your focus and take it one day at a time. Say you start with crisps: start by getting rid of all the crisps in the house (by whatever means necessary 
) if you can. Then just do one day: just tell yourself "I'm not having any crisps today, but I can have some tomorrow." Then do it again, then again - even if the crisp-free days are alternate. Once you get used to having crisp-free days it can become "I'm not having any crisps until Thursday", and then cut them down to just weekends, and so on. Then, once you've got the first covered, repeat with the second. It's just a question of breaking a habit, but it can be really hard. Remember, you don't need to resign yourself to an entirely crisp-and-booze free life to maintain a healthy weight! You just need to train yourself out of reaching for them the whole time.
(I'm making a few assumptions there ^ so just disregard it if you don't feel it characterises your attitude to crisps and booze, I'm assuming you have at least one or both most days, but do feel free to set me straight on that!)
Of course, you could try the cold turkey approach if you think it'll work better for you. My experience with cold turkey is that it isn't a question of re-training your brain (/belly), it just depends on cold, hard will power, and you might find yourself feeling resentful. Worst case scenario, you'll manage a week or two, then snap and go on a Sugar Monster rampage around Tesco eating and drinking everything in your path. What will then happen is that you'll have created an association in your mind with dieting and misery and failure: you really don't want that association as it can become a vicious circle.
I always say that as tempting as it is to try and just go hell for leather until the weight is gone, dramatic approaches are less likely to be successful and sustainable; losing slowly is frustrating, but at least there's a better chance that you will actually lose it, and in six months' time you'll be where you want to be, rather than the same weight but demoralised and scared of diets because they make you feel so grim.
(I'm certainly not against a big push to ditch a few Lindas whilst you're full of determination and enthusiasm, but when the novelty wears off it's important to go easy on yourself.)