You're not charging enough, you need to weed out the poor losers. Sad (and maybe rude) but true. The more you charge, your customer base will shrink, but the quality of customers will increase exponentially.
I worked for a very small online retail company recently (I know it's not exactly the same but in the same vein) and raising the price for $18—$40 items by $5 had zero affect on the number of people placing (sales weren't amazing but not bad).
But ya, in the first line you say you made $15k over....... FOUR YEARS? Obviously that's a bunch for some people, but certainly not MOST people in tech?? You could have made much more and had a lot more fun bartending or even being a barista.
Having read the whole post... keep it up! Just raise your prices by... like, a LOT! Like, a lot a lot!
I don't know the original attribution but it's something along the lines of "don't be afraid to fire unprofitable customers." If you have a customer who is drowning you in support tickets, and just not "getting it," politely tell them "sorry it's not working out" give them a refund and cut them off.