If you suspect MS,you really need to get into see a MS specialist. Now, that said, the MS Specialist will have to determine the extent of your anxiety. Many symptoms of MS can be mimicked by anxiety,A good neurologist can sort the symptoms out, but the answer may still come back as anxiety.
The MRI is only one tool in the diagnosis of MS. A doctor uses all the tools at his disposal to eliminate what you do not have. The MRI should be with and without contrast. This allows lesions to be most likely to be found, but a MRI can also miss lesions. That said, not all lesions are caused by MS. There are a plethora of causes. You cannot get a diagnosis of MS in one visit because it takes time to get the tests completed, read, reviewed, and then the results are provided.
Try the MS specializing neurologist route again. If necessary, you may need to visit a teaching hospital or one with a MS Clinic. I hope I do not come across as dismissive. What you are experiencing is real; I truly hope you can get to the right doctor and be well attended.