Worried about Colorectal cancer

Hi,

I feel a bit silly posting this, I'm not even sure why I am but I just feel extremely worried and I guess I just needed to get it all out.

Im 31 years old (f), I have 2 children aged 7 & 3.

I've been having stomach issues for over a year now. Pain in stomach when passing stool, loose stool most of the time or I'll not be able to go for 3-5 days constipated. I have regular bouts of diarrhoea and constantly bloated, mucus in stool and sometimes blood. I'm also so tired all the time.

i week to my GP around 6 months ago, she felt my stomach and did a blood test for celiac - all clear.

She said I might have a food intolerance so I did a food diary and couldn't really rule anything out in that sense.

I left it another 6 months until recently my symptoms are worse, I now have a constant noisy rumbling stomach and lots of gas. I have been feeling a strange pressure in my back passage and lower back ache constantly.

I work in healthcare and decided (embarrassingly) to examine myself due to the feeling of fullness/pressure and to my absolute horror I found a hard round mass (est 3-5cm) on my rectal wall. It's hard, non moveable and doesn't hurt to touch. 
I did think it could be a hemoroid but it's too hard I think.

I've got a physical examination booked for Thursday (4 days away), bloods booked for next weekend and a stool sample to drop off.

I know I'm so young and very very unlikely to have cancer but I'm so so scared, I can't even carry my 3 year old with the pain in my back. I'm classed as a healthy weight and haven't lost a significant amount recently, just a few pounds here and there.

Thank you to anyone who's read this and apologies for the long post.

K x