Issues Waking From Sleep

Before we get started, two things,

One, this is my first post on here, so go easy on me!
Two, my computer is a MacBook Pro 13", Mid 2012, running a 2.9GHz Intel Core i7 processor, 8GB 1600MHz DDR3 RAM, 750GB SATA Hard Drive, Intel HD Graphics 4000 1024MB card, and currently running OS X Yosemite 10.10.4.

Sometimes upon waking, my computer will act like it is restarting, but the screen is different. The CD superdrive makes it's normal boot-up noise, then I get taken to a gray, blurry login screen. I have to submit my password, and a loading bar pops up for about 10 seconds. Then whatever was previously opened (if anything) populates the screen. My computer seems to "lock up" for about 2 to 2 1/2 minutes after this, and is rendered useless. The cursor will not move or anything. But when it is finished loading, it is fine afterward.

This occurs at random, and is unpredictable. It can go a few weeks without doing it and then it will happen the next 5 or 6 times I open the computer.

I've had one friend relentlessly tell me it is due to what programs I leave open. It will even occur if I have no programs running.

The only thing I've known to try was to run Disk Utility and have it rewrite disk permissions that Yosemite changed from Mavericks. But I was having the problem on Mavericks as well. Do I have a hardware issue? I assume a trip to the Apple store may be in order.

I'm sure this may have been documented before but I cannot find MY situation so if it is there, please link me to the fix. Thanks!