I Have Had A Bacteria Overgrowth In My Small Bowel

I have had a bacteria overgrowth in my small bowel for probably at least a year..I was on medicine for it for the third time and I started smelling rubber most of the time..I didn't smell it the other two times when given the medicine..within days of the medicine I had went to a ENT doctor for sharp pain in my throat ( which went away now)...anyway she ran sprayed stuff up my nose and then ran that hose down my nose..she didnt find anything..I remember thinking then the bad taste and smell I had after she did that but I just can't remember what the smell was..now I'm wondering if the rubber smell is coming from that or them pills or something else..the last few days I have now discovered I have a small knot in the lower center back of my head and it itches..also a few months ago I was seeing alot of white flashes so I went to the eye specialist ..the doctor couldn't find anything wrong..it finally went away...I am constipated most of the time..and yes I been checked there too..everthing ok except for bacteria problem..my anixiety is up very high..blood pressure high..ankles and feet swollen on and off..I had alot of test already..most come back ok..memory isn't that great..what I read on the iPad is I could have a brain tumor..is this true..can you help me..I'm running out of doctors..I was fine till probably a year or so ago..