Can anxiety cause brain tumor-like symptoms? i fear that i have a brain tumor because i started getting nauseated and weak fatigued and muscle shaking

Yes.: Symptoms raising concern for brain tumor vary depending on the part of the brain they affect. Uncontrollable nausea and vomiting (without diarrhea), dizziness, vertigo or focal weakness or sensory loss in one part of your body on one side of your body would be symptoms to watch for. Brain tumors are rare, and it's much more likely your symptoms are due to anxiety. A neurologist could help.

Office visit: Especially when you're almost an adult, it's common to have these symptoms which sound functional but which might herald anything from serious endocrine disease to, dangerously, an actual tumor. The fact that you write should prompt you to visit your phyiscian. Good luck.

Multiple symptoms: All the symptoms you mention can indeed come from anxiety. But please see your physician for a good overall health workup. This can either relieve your concerns, or further investigate things so that you receive the very best treatment possible. Doctors understand when patients are worried about symptoms that frighten them. If needed, your doctor can help you get treated for anxiety also.