Note: I'll help, but I'm not responsible for any fire/damage/injury.
If I read your posts right, you have 3 55W bulbs and you want to tie all three together to a single wire that goes to the relay? From the "Basic Circuit Design" section of my writeup, I calculated ~5 amps worst case scenario for each bulb. That means the three bulbs will pull at ~15 A worst case. Therefore, from the wiring section, a conservative wire would be a 12 gauge wire. If you know you can get a high quality wire, maybe you can get away with a 14 gauge. My conservative recommendation would be to use 12 gauge wire with a 15A fuse. This should sufficiently protect the wire. If you blow the fuse too often and know you have a quality automotive wire, you should be able to go to a 20A fuse....or move up to a 10 gauge w/ a 20A fuse.
Again, these are conservative numbers and you should be ok. Again, I'm just trying to get you in the right direction, but I take no responsibility for your decisions.
EDIT: I just realized you're playing with an unsafe condition!!! You always need to size the fuse for the smallest wire in the circuit (e.g. the three individual wires going to the lights). It sounds like you're using 14G wire, so you'll need a fuse no bigger than 15A conservatively!! The other way to do it is provide a big fuse (e.g. 20 or 25 A) for the entire circuit, then provide 3 10A fuses for each light. This ensures each smaller wire is protected. Lastly, the other option which is simpler is to simply run the three lights all the way to the relay, which eliminates the complexity of a bigger wire and fusing.