That "shyness almost cost me a plumber's bill" line is so true. I read last week that people often call pros for easy jobs. They are too shy to ask for help. So they waste money on service calls. Its a huge problem that costs folks a lot. Good on you for speaking up and saving cash.
Been there. Saw a guy pay two hundred bucks because he didn't know the fill valve in his toilet had a simple twist-off cap. A quick clean would have fixed it. Lots of leaks under sinks just need a quarter turn on a supply line. Always check if something is just loose first. A five minute YouTube search can save the trip charge.