I think maybe your whole dialog is backwards.

You are basing your whole plan on the basic premise that you are "You" right now.

And your goal is to change "You".

Turn that around.

You are not "You" right now. This is not "normal". This is not who you really are. It's just the form you currently exist in.

As you move forward, you are not "changing" yourself into someone new, you are, instead, sluffing off all the shit and habits and ways of being that are not You.

Because here's the thing...

Yer gonna fuck up. Yer gonna slip. Maybe you have decided to never eat ice cream again. Well, one day you WILL eat it, and your internal dialog is going to be, "Fuck. I haven't changed. I'm just the same asshole I always was, and I have failed to change, and blah blah blah..."

Now turn it around.

"Damn. Why did I eat ice cream? That's not me! Sheesh. Glad I'm not going to do that again."

You wont BE different, unless you ARE different.

Sure, it's an elaborate self-deception of "fake it til you make it", but the fact is that our internal dialogue is the ONLY thing that makes change happen.

If you are grabbing a new coat and putting it on, and trying to make yourself fit into it, you are going to be frustrated.

If, instead, you see your current habits as uncomfortable clothes you are wearing, then take them off. Leave em on the floor.

And when you have the inevitable little slip-ups on your journey, you ask yourself, "Why did I pick up that shitty shirt from the floor, and put it on again? Phooey! I'm taking this off and never putting it back on again! YAY! Now I feel MUCH better about myself! I have looked the problem in the eye, recognized that it is not a part of what I want any more, and pointed myself in the right direction to move away from that habit/whatever. I'm back on the right track again, right away!"

Change the script. You are not changing into something else. You are getting rid of all the shit that isn't you, and getting down to your core awesomeness.

Best of luck with it. You deserve it.