Freelander 2 td4 133000

Hi All
I have been having problems with my Freelander 2, I had the gearbox oil changed and some DrTranny added by my local independent LR garage around 18 months ago, I know it’s not a fix but I’m a little confused.
1.It pulls away in auto and semi auto fine no problems.
2.There is a shudder at around 50mph and sometimes when going round bends ie exiting off a roundabout.
3.The MPG has dropped to around 28mpg.
4.I Can feel vibration through the accelerator pedal sometimes.

is this all to do with the gearbox problem?, I have been quoted around £3000 for. New gearbox, and I can’t afford that. Would getting the treatment carried out again be with the cost £280 or should I just bite the bullet and get rid .
Any insights would be appreciated.
Many Thanks
Steve

When was the Haldex last serviced (properly)?

Dr Tranny Shudder Fix isn't a fix at all, but is designed as a temporary measure to keep a failing torque converter clutch for shuddering, until the TC can be replaced.
Unfortunately it's not actually very good for the other clutches in the gearbox, as it can cause then slip, which isn't what is needed at all.
It sounds like the gears clutches could well be slipping a bit, which would explain the drop in MPG, although at 28 it's not that low. My TD4 manual only gets about 30 MPG around our Cornish A and B roads.