I replaced old spark plugs and wires and now the engine vibrates.

Hello,

I have a 1993 Honda civic EX coupe and I just recently replaced spark plugs and wires. Before I did anything to the car it ran perfectly fine,it just wouldn't start(bad ignition wires). I replaced the spark plugs and wires(now it starts)but the engine vibrates more then it did before. The vehicle also doesn't go past 40mph even when I floor it. I replaced one wire at a time so I wouldn't mix them up, so I don't think its that. My spark plugs didint come pre gapped, so I gapped them myself. if I had done this wrong could it be the reason for my problem? Also could how tight I put the spark plugs be a factor? I'm going to buy pre gapped sparkplugs tomorrow and put those in and see what happens.