I started googling my ex’s name and predicted text came up as solitary confinement... he was incarcerated... again. The only input into my phone relating to him was a text to a friend saying ‘I bet the twat is in jail again

Every time you open a webpage, they track your movements. Then, when you're on a different site you'll get ads and pop ups relating to things you've previously searched/viewed. It works the same if someone is using the same private wifi as you. Someone from Facebook came out and said they create little mini versions of people (I can't think of the word) based on their cookie and data information and can predict your browsing patterns. Which is why you might come across an ad for something that you only just mentioned. For example, I see lots of ads for studying at home. Not a coincidence since I've been visiting job ads for apprenticeships lately. Also, because I frequent this site, I get ads for IVF clinics (because obviously starting a family is relevant to my life). If you want to, you can clear your data and cookie cache, but in some places, like Facebook, it won't have much effect. They track every like, comment, click, you do.

I'm paranoid about getting spied on. Everything I talk about in messenger or instagram private messages shows up on facebook as an advertisement!
Right down to the school I was thinking of sending the kids too. Suddenly there is an advertisement for that!

I never see anything about spyware.
Perhaps you have marriage issues. I only see microwaves and freezers.

Often your gut feeling alerts you to things before you see any real evidence. If you are concerned, go into a phone shop and have them check your phone for you. Interestingly its often the guilty party who checks up on, or accuses, the innocent party of exactly what they themselves are doing.