It seems as if you're already biased towards not picking up an employment income stream (and being your own "investor").

You mention you don't have a family to support and you don't mind living on bare minimums and you have access to enough funds to build the product...

If life was a Hollywood movie where "it all works out", then staying focused on the startup would make you look dedicated and make for a possibly more appealing storyline.

But you do need an income stream.

And you need to not be operating (now or at a negotiation table) from a position of need.

If you end up so far down the no-cash rabbit hole that even an investment deal with terrible terms sound enticing... then you may find yourself eventually locked into another job: your own startup where you'd no longer have controlling interest.

Also, one does not negate the other.

Building anything worthwhile is intense work. But you can work and then, since you don't have a family to feed at home, your evenings are spent on your business.

(Except for one evening per week... which will be spent on nothing but promoting your business concept and vision to investors, media, strategic alliances, industry influencers and whoever may have an introduction or resource that accelerates your path forward).