chances of getting into dream school

First of all, this will be quite the uphill battle but still entirely possible. If you could explain to the colleges in your essays/additional info section why your grades and therefore GPA are low, this could help your case. If your reason is just that you couldn't do well in your classes, they are going to assume that the same thing will happen there. You will definitely have to make your case that you will do better in their school nevertheless, try to aim for either an underdog approach or "learn from the past, aim for the future" type of thing. Best of luck!

I think that you absolutely can get into SDSU; it ultimately just depends on how badly you want it. It'll definitely be a difficult trip to get there, considering your GPA. However, what you can do to help is do some extracurriculars. Even though you're a junior and it's a bit late, it's better late than never. If you can show admissions how badly you want to get in and explain your situation, I think you have a solid chance.