(((Krista))) - becoming aware of how often you're saying "I can't" is a good start. I'm the queen of procrastination, and don't say "I can't" as much as "I don't want to"
However, like ((Larry)) and ((Med)) said, it takes time and effort, AND sometimes you just have to make yourself.
We can't change all our behaviors at one time. Try starting off doing ONE thing you say "I can't" a day, or something like that. I've gotten hooked on FLYlady and she emphasizes doing something for just 15 minutes. Of course, she's usually talking about cleaning/de-cluttering, but it works for anything. Even TWO minutes...tell yourself "I can do ---- for 2 minutes (or 15 min)"..even sitting down and writing out a plan.
I didn't really think it would work. I have to tell myself, at work, all the time "I can do ANYTHING for 8 hours", but sometimes I have to just talk myself through 15 minutes at a time, or one customer at a time.
They say to get rid of bad habit, it's easier to start a new, good one and it takes, something like 3-4 weeks of doing it before it becomes a habit. I've been working on changing MY negative thinking for a while, but...like you, once we notice it, we can change what we're telling ourself.
Don't know if any of this makes sense...I think my brain has been a bit overloaded today, and may be on "low function" status
Hugs and prayers,
Amy