Planaria?!

Hi all, could I ask some advice please
I'm into my third week of new fish tank nitrogen cycle, have substrate - fine gravel and aqua soil, rocks, driftwood and some plants I bought from the local Aquatics centre. No fish etc as of yet. I spotted a snail in my tank earlier (fair enough), killed it, then on closer inspection I spotted these tiny little white worms on the glass and some floating around the tank. Literally hundreds. I've googled and I think they're planaria..? I'm absolutely gutted, the only way I can think of them hitchhiking in is on the plants, I boiled the gravel, rocks and wood first. I'm planning on getting shrimps and snails, and I've read planaria will kill them.
Can anyone please advise me on the best way to get rid of them for good without having to start over again? Like I said, I have no livestock as of yet.
Thank you.

Do you have pics?

Really hard to get pics, but theres loads. I've done water changes, cleaned the gravel etc. These are a about a mm long, there's some you can hardly see unless you really look, and they move quickly. I wouldn't have noticed them if it wasn't for the snail

Here is what a planarian looks like: https://en.wikipedia.org/wiki/Planarian

Do the worms have arrow-shaped heads?

FishandBirdLover said:

Here is what a planarian looks like: https://en.wikipedia.org/wiki/Planarian

Do the worms have arrow-shaped heads?

Click to expand...

They're that small it's hard to tell, but I think so.they're definitely more bulbous on one end. I've also just spotted what looks like eggs in sacs attached to the glass near the gravel, I've tried to take a pic but my phone isn't good enough

Downloaded a magnifyer, this is the closest I could get.

Remastered it a couple of times