In short, I had 5 lights on which were on a dimmer, now they don't work. Long version may include some information that is not related, but figured I should start from the beginning in case something stand out to someone. I have 5 lights recessed in my ceiling (accessible from the attic above if needed) using screw-in type bulbs. They were activated by one dimmer switch. Some time ago one of the bulbs blew out (FEIT Electrical 50Watt , 130Volt) and I replaced it with what I thought was an equivalent (Philips 5.5Watt 400Lumens, LED, 120V). It worked fine for a while (except the brighter white than the soft yellow of the others). Then one day the new bulb (and only the new one) started to flicker off and then a few minutes later back on. I unscrewed it and screwed it back in thinking there was a loose connection. That seemed to work for a while and then it started to do it again. This is where my bad idea took over. I figured that the sides were making fine contact so the part that must be loose was the tip. So like the idiot that I am I took a piece of aluminum foil and bunched it up on the tip to try and bridge the connection. I screwed it in and thought I was good. When I flipped the switch there was a pop (from the dimmer I believe) and none of the lights came on ever again. I checked the breaker and everything is fine there. Other outlets and overhead lights in other rooms are OK. I turned off the breaker and I took out the dimmer switch and replaced it with a new dimmer switch and turned the breaker back on. No luck. I inspect back dimmer switches, and they seem fine but using a multimeter I cannot get any continuity confirmed on either. No matter which wires it tap to and which configuration of on/off & dim/bright I use. I flipped the breaker back on and inspected the wires from the wall. There is NO electricity now from those wires. I went up in the attic to check out how things are laid out and this is what I saw. The line from the breaker box goes to one of the lights. There is a line from that light to the wall switch. There are many lines out of the light as well to other lights. I was not yet able to follow all the other lines to confirm if they are on a closed loop with just the other recessed lights. I wanted to confirm how the other outlets and lights on the same breaker are still functional, but was unable to find those lines yet. It appears that the issue is that no electricity is flowing through the line for the switch. Now my questions: Why is that? What should I check? What needs to be replaced? What other information would you need to know to further diagnose the issue?

Any thoughts on what the optimal spacing between fixtures is for a recessed lighting layout? I'm replacing a fluorescent light box setup with recessed in an 11 ft. by 21 foot room.