New to forum, new to Prius, new problems

First, Hi! Thanks for all the great info on here, I apologize for my first post being issues, but that makes it fun right?

I purchased a 2012 Prius v wagon in March. Seemed fine. Recently started having weird vibrations or rumbles when letting off the throttle, sometimes while accelerating. It was apparently not alarming or noticeable to passengers. I asked a mechanic friend (who does not work on Prii) to drive it and after research he was worried it was transmission related and maybe needs a fluid change or worst case scenario...
I needed a software update so I asked Toyota to take it for a spin and tell me what they thought. Fuel injectors are gummed up. So ran some cleaner through it. But, doesn't seem to have helped. Now this is getting worse. It's much more noticable and also includes a rattle. Happened on a steep incline once and seems to occur consistently when the bar is around the halfway point on the meter. A little above or below and the car acts a fool.
I've asked others with varied responses. Spark plugs, coil packs, cat converter. I research on here and I'm thinking definitely the EGR valve and related components. More research leads me to the TSB for the warranty enhancement. I called Toyota and scheduled a look-see, but that's 2 weeks away. But the guy basically said that my problem didn't involve rough idle at cold start but they would check. I'm pretty convinced this is why it's acting boggy and weird at times.


Before realizing this might be the issue i was convinced to run a bottle of seafoam in my fuel. So that's where I'm at. I don't think that will necessarily hurt (I hope) but I also don't think it will help.
*I have a few other issues with this car as well

 

Coolant level is good. It has 117k miles. But I don't feel qualified to take it apart myself. I basically know how to change oil, on my truck.
I watched a dozen or so videos about the Prius EGR cleaning, and it intimidates me.
I have been looking over the catch can, and wondered if a local shop would install that for me? I'll drop in this afternoon and ask.

Question: why did you go right to head gasket? I've read that, too. Does the bad EGR lead to blown gasket?

My basic status is while I understand a great deal about what I've learned, I am not necessarily qualified to do that work. Aka, I'm scared to.

(I also have a missing fender liner, that I *think* I can handle installing) but outside of that? A little nervous Nelly to do that myself.

 

Now I'm really freaking out. I kinda thought I had this figured out and could get Toyota to do the EGR work on warranty enhancement. But concerned they wouldn't clean the parts they didn't replace... not to mention even convincing them this is the issue.
But now head gasket, too? That prognosis is a little overwhelming.
What are the odds a person like myself, who has never done anything more than change a tire or oil/ filter change (on a gas engine) could do something as complex as this? (Head gasket, cleaning etc.)
I live in a little midwestern town. There are no hybrid shops. Toyota is 30 miles from home. What are my options? Because it's sounding like I need to park it until I've found out what is really going on.

Seems like any 'ol shop could help diagnose a head gasket. Shouldn't need to drive 30 miles if I could drive 3 to look into that....

 

Got it. I apologize, for several reasons. One not knowing a heck of a lot about the inner workings of combustion etc and two all my posts are moderated, therefore take a long time to post officially. (Gotta make sure I'm not a troll)

 

I just got back from seeing a local mechanic and they couldn't get it to reproduce what I experience when driving it. My only choice at this point is to try to wait it out for the Toyota appointment on the 19th. And run the fuel with seafoam out and see if there's any improvement.
Basically everyone so far seems to think I'm crazy or imagining it. Or think it's normal shifting from electric to fuel.