CL9 Car shakes when gearing down & cigarette fuse keeps blowing!! also

Hey guys i have an 05 euro, just spent the last hour trying to find an explanation as to why my fuse would keep blowing. i understand its probably grounding somewhere or something so i pulled it all out gave it a clean put the cigarette lighter back in its place and went to replace the fuse. the second the fuse goes in it blows :( any ideas?

2nd problem. when i'm gearing down for example doing 100 put it into third and SLOWLY gear down for like a bend at almost the top point of the clutch pedal being release the whole front section of my car jumps/rattles almost like when your about to stall on take off. any ideas? also does it when gearing down into second? i recently changed the gearbox oil with genuine stuff so i doubt its that. and it gets even worse when the a/c is on.

Any tips or ideas is highly appreciated. Thanks