Shakey wheel and less torque
 

I own a 2005 g35x recently had a tire blowout and made the stupid decision of putting on a 16" donut tire to get me home about 2-3km down the road. Stock rims are 17 and being this is an awd i know i must have damaged somethigg. Was in rearwheel when happened, but immediately after rotating wheels on the 16 my AWD VDC OFF SLIP etc lights came on but after i got home had the other tire plugged in the morning and put it on these all came off. Now i noticed right when i moved on the 16 i heard a clunk clunk and it felt like it went flat was real shakey for 15 seconds or so and then wasnt AS bad. Now i have steering wheel shake past 90km+ And i insist there is less torque... Also, bumps in the road are loud doesnt matter how small and i feel like the suspension is just bouncing away and bump i hit. I am not going crazy i know my car and it was honestly reallly smoothe. The steering doesnt feel aa tight either but im just thinking thats the new tiresZ

Did as much research to my abilities and have had this done/checked out

-brand new extreme contact dws tires
-had suspension components looked at by nissan dealer bushings etc all appear in tact
-brought to infiniti after fearing differential or tranny and they said they checksed it and appears to be completely fine but noticed a sized caliper pin. Had rotors completely replaced, pin done, new pads.. 1040$ later
-replaced rim with new one that i was driving on incase it was out of round.
No change from any of this although i had a dash rattle that alao happened because of this that now appears to be gone.
-alignments, balancing, etc done multiple times.
-tried putting into neutral during shake (still persists in neutral)

Problems are shakey steering wheel, also feels like its gonna loose it on corners when i used to be more then comfy taking them at even 110km now 80 feels worrysome. I believe less torque but it goes if i punch it.. Still doesnt feel right. Also i was just in severe rain storm and parked and put on SNOW (i think puts it in awd?) and it didddd not want to get anywhere past 3000rrpm or pick up speed at all. Not sure if thats just how the feature is it was my first time using it. 145k on car and NONE of these problems where there before that 3km drive home.
Any help sincerely appreciated! Thanks guys


Ps. Wasnt sure what forum to post this under being i dont know the problem is suspension or what..