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.

Continue with your engineering job for the short term. In the mean time, you should constantly strive to write more software and study to improve your programming and software design skill. Toy programs are good but think about a computer processing idea that you would find useful. If you can't think of any, you can try studying what it takes to study open source software and even contributing to open source projects.