The rule of thumb is that your mortgage should be between 2x and 3x your annual salary. That means for you, your mortgage should be between $60,000 and $90,000. Not $270,000. You aren't even close right now.
Peel the onion back a layer and the banks used to use a 28/36 rule. No more than 28% of your gross monthly income to a housing payment (including principal, interest, taxes and insurance - both homeowners and PMI). No more than 36% of your gross monthly income to all debt payments (car payment, student loan payment, etc.). In your case the 28% of your gross monthly income is $700. The 36% is $900. Banks are now much more conservative than they were and they are closer to using these ratios.
For a loan of $200,000 (assume you bought the $225,000 condo with $30,000 from your parents). Your P&I on a 30 year fixed rate loan with a good interest rate (5.75%) is $1167. Add in $100 per month in insurance, $100 per month in condo fees (both of which could be higher or lower) and taxes of $285 (calculated at 1.5% of value per year - might be lower or MUCH higher) and PMI of $100 per month and your payment for this condo will be $1752 a month. WAY out of your league with your income.
Loan companies don't care if you rent a room out to help with the mortgage. If you had a separate unit to rent, they would give you some percentage of the income to work with, but not all of it.
Can you afford a payment of approximately $1750 per month on your income?