STI or UTI

I’ve never had this feeling before so I’m so confused. I’ve had a water infection when I was like 13 but can’t remember the symptoms except needing to see a lot..

I’ve fairly recently had a relationship breakdown, really awful circumstances but he was a prick.

I have slept with someone else since then.

I’ve got more of like a fullness or pressure when I’m weeing, and a couple days ago had a lot of white discharge but don’t know if it was due to ovulation.

Wee is slightly cloudy. No itching or sores etc.

I genuinely feel exhausted and under the weather running round after my toddler. And I know I’m seriously dehydrated I’ve barely been drinking.

I wouldn’t even be contemplating STI if I didn’t sleep with someone else?

No judgement but I was after experiences!