@ZachHane
Pricing
Everyone probably shoots their feet a dozen times early on, I certainly did. You're paying yourself to learn estimating I guess...
Just about everyone does flat rate, and I will only do T&M for certain institutional clients now. Even troubleshooting it's [showup rate] to diagnose and then a clear flat rate for the work needed after. I hate T&M, clients generally dislike the uncertainty. I would rather eat shoe leather from bad estimates than do it.
Hours
To be clear, 2,000 hrs/year includes all incidental labor. I don't know if you're charging $125/hr
including incidental hours. If you aren't, you're underbidding. Probably, I don't know local conditions, but MA isn't cheap...
1,000 hrs/year billable (direct labor) is about the max unless you're really good at business or hyper motivated (which you seem to be, okay).
You're welcome, but well here I am at 1pm online instead of working and am new to the game, so take my advice with some salt. I hope others will chime in.
You're 30, you have a solid $100k/yr job you're content with and don't have a pressing need to be your own boss... you're very competitive and driven, and maybe your current position isn't enough, but maybe climbing the corporate ladder would be more suitable as you seem suited to a workplace environment. You could also spend your free time getting degrees and accreditation that could boost your career too. Consider that.