How does an engine damage occur?

I have a golfing problem: Yesterday morning when I went to work my TT suddenly started stuttering. I immediately ran right, waited for a while, then it went again. Since then also the tachometer pointer trembles in the stationary gas (I think I have already been mentioned here). Besides, my TT in the cold state is squalling quite strongly. Have hellish fear of n engine damage! I have now 69000 km on the speedometer. Before 3000 km the action 24H3 was carried out (which concerns d och den LMM?). Which spark plugs are in there I don’t know! Should a swap also be noted in the service proof? What should I do now? Please help me!!!