A debt of $120,000 would be insane. I would just forget about UCSD.
Considering the other two, are you certain that you would be able to borrow even the $50,000 that is needed for Cal Poly? You do not want to get part way through your degree and discover that you cannot afford to finish your degree.
Do you have any affordable choices in your home country? What country are you from?
Both Cal Poly and UW are very good. However, I would be very nervous about taking on even $50,000 in debt. Also, do not expect to stay in the US after graduation. Normally international students are required to return to their home countries once they graduate.
Also, it is not clear to me whether your employment chances in your home country would be better with a degree from Cal Poly versus a degree from a university in your home country.