Shaking violently and raw fuel smell

Hi,
I’ve got a Vauxhall Astra Mk5 (H) 2008
Breeze edition, 5dr, 1.4l, petrol, manual

The car seems okay for the first 5-10 minutes of the drive, but then:
>The car shakes quite violently, inc. Steering wheel, doors, gear stick, and with the bonnet up the engine is shaking.

>The car feels like it wants to stall when:
* In 1st gear at any point, especially when bringing it up to the bite
* In 2nd gear when travelling at 20 mph+, 3rd gear when travelling 30 mph+ etc.

>I can’t really get above 1-2 mph in first gear, and the car throws itself back and forward as if it’s going to stall even when I’ve got my foot on the accelerator.

>If I start the car within 5 minutes of turning it off, the issues are instantly present, it’s almost as if they occur once it’s ‘warmed up’.

>I’ve had it in the mechanic, and he’s replaced the temperature sensor and a leaking oil filter.
He couldn’t figure out why it was doing it either.

>I’ve also tightened the jubilee clips on the air intake pipe as they were very loose, but the issues still seem present.

>The engine management light sometimes comes on but it only reports P0170, hence why I checked the air intake pipe.

>The estimated miles remaining went from 90 down to 72 on a 2.5 mile drive into work this morning.

Any help would be appreciated!
Thanks!