I'm so afraid I have alzheimers. I want to go for the ct. What else can I do to for a 2nd opinion?

Go see your doctor. Your family doc can assess your current cognitive function and order appropriate tests to either allay or confirm your fears (to some extent). But realize there are currently no 100% accurate tests for diagnosing alzheimer's dementia although the new pet scan w/florbetapir is better than anything else we have. Regardless of diagnosis, exercise & nutrition are key to quality of life & outcome.
Amyvid... Amyvid pet scan (f18-florbetapir) is helpful in ruling out alzheimer's disease. However, a positive scan does not necessarily mean that you have alzheimer's. The tracer binds to beta amyloid plaques in the brain. These plaques can be seen in many types of dementia and other conditions including alzheimer's.
Consult physician. Consult your physician if you need an MRI scan or any additional biomarker tests.
Get evaluated. It's important to get a proper examination by a physician trained to evaluate patients with memory loss as there are many causes of memory loss.