If your issue is just that the log is too big to navigate using less, it might help to get the last lines to a file, then navigate that. For example, to look at the last 20 lines:
$ journalctl | tail -20 > temp.txt
$ less temp.txt
$ journalctl | tail -20 > temp.txt
$ less temp.txt
Instead of tail -20, you could grep for a certain date or time.
