I could have written this post myself :)
I have a daughter (my first) who is almost 9 months old. Since October I've been having head tumor worries of some kind or another. I have facial pressure mostly across my nose and under my eyes. I convinced myself I had a sinus tumor. My GP said no...it was stress/anxiety, but sent me to an ENT. The ENT did a CT scan (which of course was clear) and said it was stress/anxiety. My DH has been travelling a bit since October, and his last trip was 2 weeks long to a scary country. When he left, I started having head pressure and daily headaches. Since his return, they've pretty much disappeared, although the facial pressure is still there, and sometimes a headache during stressful parts of the day...which with an 8 month old is to be expected :) However, there's still a part of me that worries I have a brain tumor, and it doesn't help that all over social media I have friends reporting brain tumors, kids with brain tumors, people dying of brain tumors, etc.
And yes, I'm scared to death about something happening to me before my baby can grow up...but as both my doctors said, that is anxiety talking and probably needs to be dealt with above anything else. In fact, my ENT said that I need to find coping mechanisms when new symptoms arise because not every symptom means imminent death. And it isn't healthy to spend my days worried about dying/tumors/etc. when I could be enjoying my little girl instead.
So I'm a work in progress of course, but it sounds like you may be experiencing some of the same...stress can wreak havoc on your body! My headaches are usually dull but fleeting. Caffeine gets rid of them, so I use that to reassure myself that it isn't a brain tumor.
I did find that last week when I went to the hair salon (and DH spent 3 hours with our little one) that I could completely relax and be pampered. I left the salon feeling SOOOO wonderful! But the next day, the symptoms started coming back, so I reminded myself that it was STRESS, not a tumor. Tumor pain isn't relieved by a hair dryer :)
If your doctor says you're fine then you're fine. You have to listen to him/her as THEY are the ones who are the experts in medicine. They would recognize brain tumor symptoms if they saw them.
The hardest job in the world is being a mommy, and a 9 month old is BUSY!!! You're whole body could be stressed/tensed up without you even realizing it. But try to focus on the reasons why you DON'T have a tumor and see if that helps. Then try and do something to pamper yourself one afternoon--and see if that relieves your symptoms (even if its temporary--because tumors aren't temporary!)