Unlikely you would have caused immediate cpu damage, but excessive heat can shorten the life of components. The top end temperatures you mentioned are too hot for comfort but well within design limits. You will probably find the BIOS has a shut down temperature set at 70 degrees. This can be usually be adjusted (within reason).
If your CPU cooler is not up to the job, get a better one. Check the overclocking web sites for quality coolers and advice on how to fit them. In general, the more copper the better. A good quality thermal compound (eg arctic silver) can reduce temps by a few degrees on its own.
My CPU runs at 45 - 50 C (near silent system) without any problems. My HSF copes with an Athlon XP 2500 at 2000 rpm (80mm fan) and only cost around a tenner, so you shouldn't need to break the bank.