Hi, first of all you won't sound edgy sharing this here and it is totally ok. This is a judgement free space for that, lots of people also self harm here. You are not alone on that.
In my experience self harm does destress and can help dealing with overwhelming tension in a given moment, won't deny that, I turn to it when I'm really desperate for any relief, buuuut it's also true it's a momentary tool that is not good in the long run, at all, can't recommend it or that you make a habit of it. That's just the boring but true preamble.
As for similar effects though, I can recommend the classics.
Put Ice Cubes on your wrists or your preferred places for cutting. It leaves no marks and the freezing causes a very similar sensation.
Smacking rubber bands in your wrists or arms or wherever does too.
Exercise, which might not be for everyone, but if you feel the pain in your muscles the brain eats that up in a punishing manner too. + healthy. But that's the ideal one you'd turn to.
And for last, and this one only really works if you are actively trying to resist or recover from self harm and have history of cutting honestly, you can draw and trace red lines with a marker on a paper. It's some pavlovian effect shit, but if you had a habit of it, again, the brain likes it and can feed into that urge a bit.
All these might work some days, so give them a try first before actually self harming if you can.
that's my advice
I'm sure others will give you theirs for cutting secretly. That's ok too, I understand not wanting marks to be seen near family. Thighs and arms is the usual, and long sleeves and so on.
don't know under what you are that's making you turn to this form of relief, but lots of hugs at you <333
