@LorryLulu
I would say rambling for 3 or 4 pages is fine. If it helped you feel better, what does the content matter? All that matters is the answer to this question, "Do I feel better after writing this than I did before?" If the answer is yes, don't worry about "right" or "proper" techniques. Don't worry about what you "should" write. Focus on how you feel after.
If you find this hard, there are tons of journals specifically for this. One I know of is Cognitive Behavioral Therapy by Kai Musashi. I've not used it. I've just heard about it.
There also a lot of writing prompt websites for example https://daringtolivefully.com/journal-prompts
She suggests using a journal jar and just pulling one out at random. You could do that or look at the list and see if there's one that draws your interest that day.
Finally, the golden rule for a writer suffering writer's block: Just start writing. :)
I hope you've found this helpful (assuming you made it this far). Who's rambling now? ;)
~Willow