I have to say, as someone who is massively new to this - this is no right or wrong. There's no harm in asking the question, if you raise your concerns and walk away with any additional % - excellent. But the thing you don't want to do is alienate the others, so be sure of your approach before you voice concerns.
Nobody here will ever be able to understand the effort/risk you have all put in comparably apart from yourself, so the only advice I'd give is go for what you can get, nicely.
Unfortunately, you have already made the mistake of waiting seven months. As soon as they reneged on paying you the "imminent" cash salary, you should have demanded a much higher equity stake than low single digits.
At this point, you have the right to ask for whatever you can get. It's just a matter of what your alternative is, and how valuable you are to them.
Should I try to line up a job before negotiating?