If i had a brain aneurysm that burst 3 days ago & did not seek treatment, could i be feeling quite a bit better now?

Doesn't seem likely: It a brain aneurysm burst it seems unlikely you'd be here 3 days later writing to tell us about it. Most people describe the worst headache possible and it's considered a neurosurgical emergency if indeed it's an aneurysm. You should check in with your doctor right away if you have headache symptoms that come out of nowhere like this.

Possible, not likely: A subarachnoid hemorrhage from a ruptured aneurysm is usually no subtle event and recovery after 3 days is not very common but this scenario is possible. The issue is that if you have an aneurysm that ruptured then you are at significant risk for a re-rupture within a few days to weeks and a second time rupture is usually worse. You should probably discuss the details with your doctor to be safe.

Unlikely: Do not worry, as you have not experienced a ruptured aneurysm, but if you have started to experience new headaches at age 62, you need medical attention to discern etiology, as there may indeed be risk for future problems.