Of course none of us can diagnose you. But brain tumours are relatively rare. Going to a doctor won't help with your anxiety. It will temporarily ease it - but in the long run, repeatedly going to your doctor will not help anxiety but in some cases it may just make you even more stressed. You ask anyone here, and you have actually confessed to this yourself, but you know that temporary ease is… well, it's just that - it's "temporary" i.e. it doesn't last long. So it should be of no surprise that your anxiety comes right back soon after being reassured. This is why you need to deal with the cause of the problem rather than with the symptoms of the problem.
First of all, I will speak about my current situation: tingling and headaches are common symptoms of anxiety. Especially headaches. I suffer from headaches which usually last for a week at a time. Right now I am suffering from headaches. Whenever I do something that requires a little concentration, my headache slowly builds up and up - in the temples and forehead that is. Tingling sensations is a symptom that I can actually provoke. I just have to think about tingling sensations in my face and then they appear. It is the same for most of my anxiety symptoms now because I learn what my symptoms are. I also get numbing sensations. Whenever I think of the sensations, they come. Whenever I don't think of them, they are not there.
Now, my advice for you to control your anxiety is as follows: the best way to overcome anxiety is to learn your symptoms. To do this, I recommend you keep a log/diary of your symptoms. You need to write down your worrying thoughts and the symptoms you are currently feeling with those thoughts. It's also a good idea to rate your anxiety level from 1-10. Keep doing this for at least 2-3 months. After you do this, you will be able to go and look back through your log and learn the patterns. When you can pick up on certain patters, you will start to learn how your body reacts to anxiety - i.e. you will learn what your symptoms of anxiety are. At any time though, new anxiety symptoms may appear and this may make you anxious. That hardest thing is when new anxiety symptoms come. Its best to have a method of learning your symptoms. I usually take medication but if it doesn't work, that's an indicator for me that the symptom is caused by anxiety. I also try and concentrate on when the symptoms both appear and how severe they are at the time.
If my symptoms are exhibiting themselves more when I think about them, once again, this is another indicator that it is more likely anxiety. If, and when my symptoms stop when I am not thinking about them, at this point, I am pretty confident it is my anxiety that is causing them. But learning this alone, doesn't help prevent the symptoms. I just learn how to control them. And more importantly, I often use other anxiety symptoms as a cue in figuring out whether other symptoms are due to my anxiety. That is to say, if I am experiencing a new symptom and I don't know if it is anxiety related, I will often see if other anxiety symptoms are present. So for example, I know that the numbing sensations in my face is definitely an anxiety symptom. If I experience a new symptom, lets say abdominal pain, if during the abdominal pain, I am also experiencing the numbing sensations in my face, i.e. the two symptoms are in correlation with each other, this is also another indicator that the abdominal pain is also caused by anxiety.
But understand that I am speaking about my own experience - for everyone else it may be completely different. You may not experience anxiety in this way. I am only using my own example for guidance for you. Sometimes I will feel abdominal pain without numbing sensations and sometimes I may feel the numbing sensations without abdominal pain. It which case I will use my other methods of discerning what is anxiety related and what may be due to an actual physical problem.
To finish, brain tumours often exhibit themselves when the tumour has grown quite large but this also depends on its location. Due to this fact, headaches and tingling sensations may be the only symptoms from a tumour but it is more likely that you will experience other symptoms such as seizures, dizziness, eye/vision problems, cognition problems, problems with movements, hearing problems, etc. depending upon its location. But seizures, dizziness, eye problems, headaches are symptoms of ALL kind of brain tumours (this is because these symptoms are due to intracranial pressure).
I am no doctor though. This information is from what I have learned with reading and hearing out others who have either suffered from brain tumours or have had family members who have suffered. But never take my word. You need to learn your body yourself.
More importantly, don't let the problem worry you too much. This is the most important thing to remember. Even if you was actually suffering from a physical problem, letting your anxiety overcome you is the last thing you would want. We are all here for you to give you advice and help you along the way. But it ultimately lies within your own thoughts. And you can do it. You can beat it.