It is normal to be anxious and scared. I think everyone on this forum can empathize.
Get the colonoscopy. Whatever the results are, you can handle it. I have two daughters, ages 5 and 2. I also have no family history of colon (or other) cancer. I was diagnosed 5 weeks ago and am 2 weeks out from surgery. I also wish I had gotten my colonoscopy earlier, but it probably wouldn't have changed much. Many of these cancers are slow growing.
Anal fissures are usually pretty painful. Even if you have internal hemorrhoids on anoscopy, get the colonoscopy. I was reassured when anoscopy demonstrated internal hemorrhoids. Turns out I had both hemorrhoids and colon cancer. So, my advice would be to get a referral for colonoscopy from your PCP already and try to turn your GI appointment into a colonoscopy appointment. May save you a week or two of worrying.
Stage IIA rectosigmoid CC (T3N0M0)
Dx 6/5/17 @age 41, mom to 5 & 2yo girls
Workup: c-scope, EUS, rectal MRI, CT C/A/P
AdenoCA 5.5cm, WHO Grade 2, 0/22 LN, no distant mets
CEA 1.9 (6/5/17)
No lymphovasc/perineural invasion, clear margins
MSI intact, OncotypeDx pending
Lap sig colectomy 6/23/17, no ileo/colostomy
?adjuvant chemo with Xeloda