Will habits will form if you're persistent at it after 3-10 weeks? (with a personal touch)

Curious, because I used to and still like programming. But I haven't coded ever since my parents passed away in a car accident. Now, I'm feeling ok to try to get back into it, but I have big issues with rumination, lack of focus and thoughts that keep coming in my head. And I just can't seem to start, I become anxious and I get blocks like "I can't do this."

Now of course I can, it's more that I realize that my brain is more like that it doesn't want to, rather than not being able to.

So I've been thinking, if I just start forcing myself to code and to read, will I eventually get used to it and it will be ok? I need to do it for career.

And how long do habits approximately take to form?

Thank you.