There is a port that is already being used before starting Apache, preventing it from starting:
21:16:12 [Apache] This may be due to a blocked port, missing dependencies,
21:16:12 [Apache] improper privileges, a crash, or a shutdown by another method.
Could you check if you have installed Skype? By default it makes use of port 80. If this is the case, could you disable this behavior?
If not, you probably have another Apache server running at that port. You can only use one port at once, so in order to get it working, you must change the XAMPP Apache port or disable it on the other application.