I don't know what DMT is or what it's possible side effects or consequences may be.
I rather doubt it could "cause" an aneurysm as aneurysms are caused by clogged arteries.
I think the "large and erratic" pulse you were feeling had more to do with your state of panic as opposed to an aneurysm.
An aneurysm is known as a "silent killer" because there are almost never any symptoms........until they rupture. If they DO rupture, you begin to bleed to death internally and if that is what you fear happened to you, I'd not worry. You wouldn't have lived long enough to be writing this two days after this "attack."
The blurring of your vision and feeling like you were about to faint are very common symptoms of panic attacks, which I believe this was. Searching symptom sites on the Net can give anyone panic attacks. They can have you believing a bout of sneezing is a brain tumor. Stay off them!!!
Like I said, I'm unaware of what DMT is or what it can or can't do to damage your body, and while I believe you do not have an aneurysm nor did the smoking of this DMT cause one, I firmly believe you should seek medical attention to be on the safe side and for your peace of mind.
When you see your doctor, you must be completely honest and tell him/her about this drug you smoked.
My non-medical opinion is that smoking this substance caused you to have a fairly major panic attack. But that is just MY opinion. The important opinion you need is your doctors!