Procrastination has always been one of my biggest hurdles in life. What helps, and God knows I'm not saying I got this thing by any means, is to break any task into teeny babysteps. I tell myself I just have to do this one little thing, but I almost always do much more once I get started.
The other thing is to not overthink simple tasks. If it's easy enough, just do it, however imperfectly.
Things that I really hate to do, I try to do first, so I can tell myself it's all downhill from there.
Maybe you could tell yourself that you're going to adopt one helpful habit per day, not go on a diet immediately? Kinda sneak up on it and before you know it, you'll be chugging along towards your goal.
Hope this helps.