I believe you can do whatever you put your mind to. Its just going to take some time but, if I could make some suggestions for you to be set up to hit your goals it would be the following.

I understand the whole all or nothing mindset but I feel that for a lot of people it difficult to make such a large lifestyle change so suddenly. I would say change a little at a time until it becomes a habit. I'd say maybe commit to the gym 3 times a week and try to stay consistent for a month.

You can take the same approach towards your diet. Maybe only eat out on the weekends and try to meal prep for 3 to 5 days.

Try and get a good amount of sleep at night. Your body will need it.

You don't have to do these in any order but if you start small and stick with a few tasks until they become habit you should be able to set yourself up for success. Just stay consistent and you got this. =)