Am I bound to have blood clots or any other health problems?

I'm not gonna lie. I stay sitting a lot to play Minecraft. I usually stay playing it over 6 hours. I used to do exersise but I can't anymore because this treadmill we have broke so I can't use it. I've stopped in April or May. I've been playing it for about over a month. My legs feel sore (like when you do too much exersise) and I haven't done any exersise.
Note; I'm 17 and I'm not overweight.

Stand up every half hour and walk around for a minute. No treadmill is needed.

Yes, you can get a blood clot from sitting 6 hours.

If you're not stopping for a bathroom break in 6 hours, you're either not drinking enough (not alcohol), or you're wearing a diaper.