Given people wanting to donate to support you and an apparent issue being the inability to earn sufficient profit margins, why not organize as a non-profit instead? You're clearly trying to perform a socially-beneficial service here, focusing on underserved populations. Missions like that are the entire reason for the 501(c)(3) carve-out and you could potentially survive if you didn't have to earn profit or pay taxes. Most states even allow you to apply for hardship exemptions to property taxes, which can help a lot on office expense.