Can’t find financing due to income

Hello, I am 21 years old and looking to buy a property. I want a duplex, but am willing to settle for a SFH since I'll have roommates renting out from me as well. The only issue is that I can't seem to find financing. My work history is inconsistent with working different jobs in college. I am in the national guard and get money for school, but that doesn't qualify towards my income. I have tried using my parents as co-signers but their debt/income ratio is too high. I have asked other people about co-signing as well, but nothing has gotten anywhere. I am sitting on a big chunk of cash for someone at my age and I don't want to waste the opportunity being constrained by my lack of income history. If anyone has any suggestions or would be greatly appreciated.