Should I get tested for STDs

If you're worried get tested. If you're not sure, get tested. If you have a new partner, get tested.

If you're worried it's always worth getting checked.

You can get tested at any local sexual health or contraception clinics.
They are free, confidential and it doesn't have to go on your medical history.
Most have walk inside but you can also call up and make an appointment

I'm kind of wary of asking for medical help, the past few times I've gone to the GP they've pretty much shamed me for making an appointment and wasting their time because it turned out there was nothing wrong with me.
First time it was me checking my moles that looked different and she spent a good 10 minutes lecturing me on how I shouldn't see a gp unless it changes shape (mine had become risen which apparently wasn't a good enough reason to get it checked out).
The second time I was worried my hairline was receding which would be terrible at my age and he drilled me on exactly what I googled, what I read, what the exact website was, and just 'why oh why' I had decided that coming to the GP was a good idea. He literally used that phrase.
I know realistically I probably don't have STDs because I feel completely fine and my ex never had symptoms either, and I just want to check for a piece of mind. But every time I go to the GP with this mindset of 'just checking for a piece of mind' I get told off like a little kid.