You received some very good advice from Jaquta....I would only add that you might consider a trial of the anti anxiety medication to see what happens to your symptoms before you go on to exam the brain tumor issue, and if your symptoms go away, then you and your doctor may decide not to go any further.
Just trust that you'll get to the bottom of this problem and try not to stress too much in the mean time.
A lot of the symptoms you describe can be attributed to anxiety.
I saw my GP prior to Christmas because I was feeling tired, faint, lightheaded, etc. He said these were anxiety-related.
I suspected some were due to me not eating very much at the time too.
Excess or intense exercise can make you feel dizzy too.
Hyperventilating can cause visual disturbances.
Some side-effects from the citalopram can leave you feeling nauseous and lightheaded.
Trust your doctor and let her treat you.
The side-effects from citalopram? For me personally, after the initial nausea this medication had fewer than most others I tried.
I think its normal to have fears about certain medications. The benefits of the medication should outweigh the negatives. If not, talk to your doctor.
I would actually strongly encourage you to accept treatment and deal with the problem straight away.
I wasn't very insightful about my illnesses for a long time and I find it quite depressing looking back over my life and seeing how much of it I have lost due to me not trusting others and their evaluation of the situation.
Just take things a step at a time and you'll manage.
I think you should visit this site
it will give you a lot of information