Panic Attacks Support Group
A panic attack is a period of intense fear or discomfort, typically with an abrupt onset and usually lasting no more than thirty minutes. Symptoms include trembling, shortness of breath, heart palpitations, sweating, nausea, dizziness, hyperventilation, and sensations of choking or smothering. Panic attacks can be very sudden, appear to be unprovoked, and are often...

If she is a good friend to you, than she will always be there for you and should be very happy for you that you are buying a house.
Look after YOU, that's who is the most important in this whole situation, and your friend will also do the same with herself :)
You are not dumb as everyone else has said, I am like you, I care WAYYY too much about what others are thinking about me or about a certain situation, if she is a real friend, then she will surely understand and hopefully she can get renters in there ASAP!!!
If crying makes you feel better do it, I find that crying usually makes me feel 100x better... :) If you just need to get away from it all and have a good cry, I say go for it !!!!!!!!!!
In the end it will all work out..It always does.