I think I messed up my LED

I was having some soldering success at first but then it start progressively getting more difficult as the tip wasn't melting. I then later found that the solder that gets collected on the side messes with the soldering iron and that only after touching that side portion of the iron tip with solder residue will it start melting the solder.

In any case, I there are unfortunately some brownish yellow marks on the LED now and it doesn't work anymore when I try to connect the alligator clips to a battery source. So yeah, I think I messed that up. I get the feeling I need to clean the soldering iron tip so if there are any advice one could give me, I'd really appreciate it! lol