Dumb question but why don't you get some help with sales and marketing. Even some affiliate marketing to increase usage.
Generally I would say try to minimize the amount your spending per keyword - broader search terms or the broader options on those search terms always cost more.
Might help a ton if you renamed your software to something that is more searchable (or just add some kind of name on the end or start)
For something like this I would probably start at like 30$ a month and keep optimizing - worst case you lose only a few hundred over the course of a year.
But it is almost impossible to get any worthwhile traffic from Adwords in 2022 (in terms of volume or quality) at 5 cents a click.