Website not improving for 3 years

I feel so discouraged having had a website for 3 years and I still haven’t reaped any noticeable benefits coming from it.
I used to write content once every week, only a couple ranked. For the past few months, I stopped
putting up new content because of school. Now I graduated and I have the time but I don’t know where
to start. The few posts that had ranked are no longer in the first page. I’m barely getting any views or clicks.
https://imgur.com/a/DCfPrAs
In the analytics and performance images, you can see how much my website has deteriorated. It’s like I’m
back to level 1. I made this website in the hope that I would have a personal income and become independent.
I’m only 17 and I have so much to learn. I’m still hosting this website thanks to my father’s support, but I
fear that he may tell me to take down the site as it’s useless and wasting money.
Can someone please give me an advice? I chose this niche because it’s something I’m interested about.
I didn’t know it would be this tough.
Here’s the site: guition.com