Hi guys

I feel I need to message this to help get it off my mind.  found a breast lump approx 1 week ago - no skin changes, no pain, no redness. It feels hard like a marble and it can roll when I grip it however does feel quite deep when I press down. 
I contacted my GP about this and she asked me to wait until after my period to monitor the lump and it still remains to contact again and we can reassess - due to my hormones. 
my period is due to finish in the next day or so and unfortunately the lump is still there. I was okay and not thinking about it 24/7 for a few days there however with my period ending soon I keep being reminded I have to do something about this again and it’s worrying me 24/7. Yesterday it’s been on my mind that much that I’ve been researching things, I now feel like I have a dull ache / dead arm sensation in my L arm ( the side where the lump is on mg breast ) 

I can’t help but feel this is linked to the lump and I am driving myself crazy. I have no family history of breast cancer however despite my age I can’t help but feel this is something more serious. 
I will phone my GP again in 2 days time when my period finishes and hormones settle down. 

the reason I’m posting this is to see if there is anyone else around similar age to me that has had any of these symptoms / has went through something similar who can give me any advice / reassurance / what to expect going forward. I suffer from a lot of health anxiety which I feel is contributing to how I’m feeling.