Erm yes, that's probably a LOT to do with your current problem. What do you mean you broke the shocks by bashing the gear knob? Don't understand what you mean.
If you've hit the ground with the underside of the car, you might want to check you've not damaged the sump too.
Cutting a long story short I had the gearknob off (this was the old one which was ill-fitting) and thought I'd put it back on properly... but I hadn't, so when driving the gearknob came off in my hand... not realising the gearstick is quite fragile I attempted to force the gearknob back on the stick by whacking it (silly I know, lol) onto the stick. The gearstick then fell down through the floor. Basically by whacking it I'd snapped the bolts/rubber shocks which held that part of the box onto the underneath of the car (directly underneath the gearstick). It dragged on the floor for approximately 20yds at about 2-10mph whilst I pulled over, got out my AA card & mobile

Having called the AA out he strapped the box part to the floor just to get me home. It was then fixed (2 new rubber shocks bought & fitted by steve@minifixit ... seem to be there more than I'm at home at the minute! lol) and a new gearknobfitted for good measure.
I didn't hit the ground or a brick or anything so nothing else should be damaged. The shuddering in 1st/2nd has always been a problem since I've had the car, it hasn't just started or got worse since that "accident"..
have you got MSN mini slapper?