House Hacking in Oakland while supporting family (tight budget)

My husband I make about 140k total per year before tax. We live in a tiny converted garage studio in Oakland for $1400 per month. We also support extended family. This is a very important value to us and nonnegotiable. We pay my brother in law's rent of $900 at his college in SoCal plus his food and we pay his college tuition of around 24k per year. There is chance that another family member will be starting college at a junior college and possibly moving in with us next summer. To pull this off, we would need to move into a slightly bigger apartment. 

I am very determined to make all this work and still make good financial steps to the benefit of all of us. We have a total of 24k in savings, but we will do our very best to keep increasing that. We will also work to keep increasing our salaries, but I expect steady rather than sudden increases.

I keep wondering if there is any way to use house hacking to get into a two bedroom unit in a multifamily property so that we could purchase a home and keep the mortgage payments low. But I'm starting to feel like this may be foolish and/or impossible under the circumstances. I would appreciate any thoughts or advice from anyone. Would it be impossible to get a duplex or triplex with 3.5% down and mortgage minus rents under 2k?