Cat Converter Light vs Bad Fuel vs Burning Oil

[Ranger]

Hi all

Hoping you can share if you've had similar experiences I've got with my 2011 Golf 118TSI (has had the notorious update).
Problem: Last night filled up with 98 from United (not ethanol mix), which I haven't had problems with before.
This morning - take off onto main road, drop back to 2nd, hit 3k rpm, loses power. Shift up and keep driving. Thought it was a cold turbo.
Get into 3rd later and does the same thing at about the same level. Pulled over, turned off, restarted, had no further problems on my 50min commute.
Driving home tonight from City, all good for about 40 minutes when started doing again. Kept driving, got home. Called a mate who suggested some stuff and that it could be bad fuel.
Drive to football, I think it was OK. Turn on car after football, Cat Converter light comes on. Drive cautiously home.
Please note that if I didn't force the car and drove to the gear change suggestions it was good. No shuddering or anything else.

Thus far I thought it was just fuel.

But she also drinks a lot of oil. I only had her serviced 2000km ago (no codes0 and she's through half the oil. I topped up on the weekend and seems like a bit of that is gone (do several hundred km/week). The mechanic did talk about putting in a catch can. But am wondering if this burning oil is clogging up a sensor or something.

She is running as smooth tonight as she was before I put in the United 98, except for the loss of power when pushed.

Unfortunately like most families with kids I rely on a 2nd car but I am probably going to have to get her put in tomorrow for whatever needs to be done - unless you think she can be safely driven to a degree.

Thanks for the help guys - hopefully can make it up a bit with my Nexus 7 install pics

[Ranger]

Just something else, I noticed after my commute home tonight after I turned off I didn't get the intercooler noise cooling down, if that's what it's doing...which I thought was weird.

[Ranger]

OK got an update. Called mechanic and he said he'd check codes, though he thinks it could be an air sensor due to something (can't remember...). Didn't drive her today, though he thinks it *should* be ok to drive it within reason.
This afternoon started her, cat light still on. Drove around the suburb to warm up oil. Then onto the 70/80 zones to the shops, always staying on recommended gears. No problems.
After shops started pushing close to 3000rpm in 2nd and then in 3rd, no power drop.
Pushed a bit harder to about 3500rpm, no problems.
Drove home, gave a few gentle revs, seems ok though maybe ever so slightly less on rev.
Turn off, radiator fan (or intercooler?) doesn't keep running, which again is weird and is concerning.
10 minutes later took oil level and was almost 2/3. Interestingly enough the plastic tip of the dipstick was hot AF.
So will get the codes checked next week and go from there.

[Ranger]

For all those playing at home (ie no-one), today I drove her for 105km. Kept all within reason and she was fine. A few times when i pushed up to 3500rpm she was fine and sometimes she dropped off. Also the radiator fan kept on 3/4 times.
Water and oil temps were fine, she sat on cruise along the motorways, no shaking etc.