Check engine light on then blinking while engine vibrates

Hi so I'm new to this forum, new to any forum actually!

I have a 2010 Hyundai Accent GS. I bought it a year ago from a dealership, it only had one previous owner and was in shockingly great condition. It's never been in an accident and it had 58,000 when I got it in June 2015 and now has 69,000 in April of 2016.

About 2-3 months ago I had a crankshaft sensor problem and it was replaced/fixed for around $160 with my mechanic who I've gone to for many years and trust. That's been the only problem all year until tonight when as I was pulling into a grocery store parking lot the check engine light came on and the engine felt like it had a jolt and then started mildly shaking. I pulled over and turned the car off and then started it up again and headed home because I was worried I would get stuck somewhere.

I'll take it into the mechanic tomorrow morning but I am doing my own research and would love a second, or many second opinions!

It currently starts up fine, and for the first few seconds the check engine light is just on, but then about 30 seconds later it starts flashing/blinking at a moderate pace. When I opened up the hood I could see that the engine itself (while on) was vibrating, pulsing, rather shaky so to speak. Inside the car with the hood shut while the car is running it doesn't sound loud or very aggressive but it's enough to have me very concerned especially mixed with the engine light blinking.

I've researched and am guessing it may be "cylinder misfire" "coil" "belt" or "spark plug" issues ??

Also I checked my gas cap and it's securely on. The car sounds fine in idle but I'm worried that it's unsafe to drive it to my mechanic even though he's only 3-4 miles away. I don't have triple A right now so I'd prefer not to have to get it towed to the mechanic. Also can anyone give me an idea on the price range it would cost to fix some of these possible issues? I'm completely broke and out of warranty due to the transfer of title

Please help! Thank you!!!