Are your dreams entirely dead? No.
There are Low GRE/Low GPA success stories all over this forum. Mine included. I performed abysmally my first 3 semesters in undergrad, and it wasn't for a lack of trying. I spent my last 2 years trying to make up for it.
When I graduated, I had an overall GPA of 2.85. I decided to enroll in a science post-baccalaureate program in order to boost my GPA and figure out exactly what I wanted to do career-wise.
I was able to increase my GPA to a 3.08, allowing me to at least meet the minimum graduate school requirements for most programs.
My GRE scores are decent. I also got a job related to my field, allowing me to gain some research experience and obtain some great letters of recommendation in the process.
I'm going to graduate school in the fall, and I'm very excited about it!
There are some schools out there that are willing to overlook an underwhelming GPA. You will have to work harder than some, and your path will be a bit curved, but you can do it.
Work experience, strong letters of recommendation, good GRE scores, and a great statement of purpose can offset a "bad" GPA.
As for whether or not you should double major, that's up to you.
If you plan on moving forward with psychology, it would be beneficial to double major. That would allow you to hone in on your interests and decide exactly what you want to study in the field of psychology (if you don't know already). Plus, you only have 16 more credit hours. That's like 6 courses? You might as well just finish those classes.
But, if you decide to graduate, you could take some graduate-level courses at a local college, which would help GPA-wise and show graduate schools that you can handle graduate level coursework. And work experience always helps!
I would imagine that while most graduate schools set the minimum GPA requirements, the actual psychology program is going to be more concerned with your performance in your psychology courses, which you are doing well in. Not all hope is lost.
It's "difficult" for anyone to get into a graduate program, no matter how awesomely high (or low) their GPA is. That doesn't mean you shouldn't try. If this is what you really want, then you need to be willing to do what you must to make it happen.
No one said it was going to be easy.