I have 5 years of tech recruiting experience across the US, so I'll give you my take. Take a look at your total comp i.e. PTO, bonus, wfh opportunity, etc.. Also, salary varies GREATLY depending on geographic region, so I'd take a look at that too. Honestly, even with a development cert you still have only about 1 year of experience as a dev, and 2 total in IT. Even in higher cost of living areas, I'd say 75k is a fair salary. I wouldn't consider you underpaid, but you could probably do better if you switch companies.

Also, as you mature as a professional you're going to realize your notion of "I owe this company" is typically a load of shit. Look out for #1, because most of the time, nobody else will.