Career change into Programming

I hate my life. I should have done software engineering instead of mechanical engineering. I'm already 5 years into my career making $75k. Is there any chance of moving into programming with a lateral move or do I have to start over? I don't have much to show for though I have programmed as a hobby on and off since high school. I have made some shitty tools and calculators for work and written some firmware.

No, don't read SICP, it's a mental masturbation book for soft freshman brains. Programming is a practical skill not theoretical, just start hammering away at real-world stuff like walking directories recursively or making a hand-rolled news feed.
SICP teaches important things but it's very verbose and filled with irrelevant problems, and actual programming will make you learn all that anyway.

Forgot to add that Python is a great first language as it's simple, has lots of good free libraries, and ample learning materials all over the Web.