Good to hear these sorts of things when trying to develop your own plan for your startup. My approach (which MANY will say is a failure) is to build in the evenings and keep a day job to cover personal expenses. The ultimate goal being, once we gain traction, go into the company full time. With the situation I'm in (fairly serious gf and finishing uni soon), this seems to be the best route. Thoughts?
It can work, it just takes longer and is harder to maintain the momentum when you are only working on it in small chunks.
If you could drop to part time work to cover the expenses then that might be a more viable approach but unless your startup is launched and generating revenue (even 1 sale a week) within 3 months you will notice that it gets harder to keep going, pivot and really get decent traction.
Or, save up and take 9 months off. That's what I did, if my money ran out after 9 months I was prepared to do "urban camping" until I was making enough income to live in some proper digs.
Ironically, the startup never even launched, I ended up moving to San Diego, and building another startup which is successful (6 figures of revenue per month in 8 months).