I would not do Business Admin alone - double it with finance or some other complimentary major. I have known many business majors who are too generalized to find a decent position right out of college - unless they went to a top school and had impressive internships. If you choose this route you would need more than a high GPA to discuss in your interview and to put on your resume. Leadership experience for clubs/organizations, internships, and part-time employment in a business setting are all important.
Minoring in psychology can be useful (I have a BA in psychology but would not suggest majoring in it unless it's doubled with something else - I moved into Human Resource Management). But a minor is useful for business administration - not so much for accounting or engineering.
Are you able to contact people in these fields and try to do some job shadowing to get some real ideas on what life would be like working in these professions?
If you are concerned about math, you may want to look at the engineering programs to see what they require, as these are intensive programs that require dedication to succeed.