In November I had a really hard and uncomfortable bowel movement (felt like I was trying to poop a razor blade) but I thought nothing off it. Then a few days later I noticed alot of bright red blood on the toilet paper and in the bowl. Again, thought nothing off it as I've had hemorrhoids off and on since i was about 16 (I'm 29 now). I live quite a sedentary lifestyle. I decided to take a bath everyday and after a few weeks the pain (pooping a razor blade sensation) and the blood largely subsided.

For Christmas I bought myself a bike and over the holidays cycled about 15-20 miles.
Then on New Years I had a bowel movement and noticed alot of bright red blood, and the same again yesterday. The movement wasn't as painful as before, but there was a slight 'pooping a razor blade sensation'.

This morning I decided to inspect my anal area and noticed a blue/purple like colour around the anal opening (not sure if this is normal). I also noticed a red circular spot which sort of looks like a cut. I'm not sure how to describe it so I took a picture because it was the only way I could see what I was looking at -

WARNING LINK TO GRAPHIC PICTURE - https://i.imgur.com/5WV7FqU.jpg

Apart from this I feel quite healthy, eating normal, no abdominal pain etc. I'm so freaked out the blood might be something very serious like cancer. I dread going to the toilet.

You need a proper diagnosis by a GI doctor or CRS. Otherwise you may not get the proper treatment. Don't wait, because if this is an acute fissure you will have a chance to heal fast but only by proper treatment. It looks like you have a hemorrhoid and a fissure, but you need an examination by a professional. Just eating normal wont do, you need to exclude all constipating foods that make your stool even slightly harder. Unfortunatley normal stools are harsh for fissures. You need stool softeners and strict diet. For me the hardening foods are grains, nuts, sugar, dairy, rice. Also if you have a fissure, do request muscle relaxant ointment and star applying ride away. If you wait, this may become chronic and i cant even begin to describe the nightmare.