2011 Opel Astra 1.3cdti StabiliTrak issue

[Stanlex]

Hello, I'm new here so if I do something wrong, please do tell me.

I was driving today and a message came on the little screen telling me to service StabiliTrak. An actual traction control light and a service traction control light also came on, and remain on when I turn on the car.

Things I noticed since the light and message came on:

1. When I change gear from 1st to 2nd and 2nd to 3rd, the car suddenly judders. The same judder as if I let go of the clutch too early.

2. I have an electric handbrake, which disengages automatically as I begin to drive off. It no longer does this. When I try and drive off, the handbrake remains on and the car doesn't move.

3. While I am driving in third gear for example, and I tap on the accelerator gently in quick succession the car begins to judder violently. This happens in most gears.

I will be bringing it to the Opel dealer where I bought it from to get it checked out and then hopefully selling it once they fix it. I've had the car since Oct '13 and it's been nothing but problems.

1. Car made loud noise front and back when going over bumps.
2. Battery was faulty, they replaced it with hesitation. I had to jump start the car at least 20 times in the space of a month.
3. Lights come on and go off.

Since I bought it, I have made about 10 trips to the dealership regarding the above issues.

It's just been such a pain and I really want to get rid of it. I have a feeling like it's going to be constant bad luck with this car.

Thanks for the help!