I posted this in r/advice but you ladies always have great suggestions, so I thought I'd pop over here also

I'm going through a bit of a messy few months right now, and I am constantly told that to make dealing with this easier, I need to make sure I am taking care of myself. Usually followed by examples of getting enough sleep, eating right, drinking water etc.

This is great advice and I really do try and take it on board, however, I actually really struggle! I grew up on fizzy drinks and microwave meals. I didn't have a strict bedtime so became a full blown night owl.

I hate this, but it is ingrained into me. When I am hungry, I'll just eat some bread and maybe a chocolate bar (yes, this include dinner time). When I'm tired I'll drink a fizzy drink. I never got into the habit of cooking or sleeping well. Also, I am very lucky that my weight has never been a problem, I'm naturally very slim so I never even had to watch my food in fear of weight gain or anything.

In short, I am clueless. In order to take better care of myself I would have to do a completely u-haul which is fine by me, but I don't even know where to start or how.

Does anyone have any ideas of small changes I can make in order to keep this up over the long term? If I try too much at once it never sticks. I need to play the long game here and come up with something sustainable.

Extra info: I'm female, 25, single and live with my mum. I work an office job in my chosen career (I love my job). I don't have a gym membership but I do have good equipment at the house.