How can I lower my college debt ASAP?? (private loans)?

its pretty high and i only have a bachelors degree so i dont make alot of money. I fear i will never be able to buy a home if i am single. The problem is its mostly private loans with a high interest rate. is there a way to consolidate it to a government loan with a better interest rate. I've been paying for 4 years and i have never been late.