Other Ways to Reduce Lag?

Hi guys,

I'm not a super computer whiz when it comes to coding or computer hardware. But I was wondering if you guys could suggest ways to reduce in game lag?

Sometimes throughout the day when I play I experience types of lag such as:
- Delay in moving through portals from map to map (I will press the Up key on the portal but the map will not change until a few seconds later)
- Random spontaneous D/Cs when training or PQing or in a map with lots of mobs.
- I will constantly hit mobs over and over again, dealing damage, but the damage does not deduct from the monster's total health until multiple seconds later.
- I will die, press the Ok button to be revived, but I will not revive and remain in the map which I have died. I need to relog and try again to resolve this issue.

I do notice this does happen especially when family members are streaming content online (Netflix, youtube, etc.) so I'd imagine its mainly because they're using up the bandwidth (idk if this is the right term)?

After doing some research I saw someone mention on the forum to subscribe to WTFast. But idk if it's worth it (i.e. if it actually works or is just a scam?) just to have better/reliable connection for ML? When I search games they support on their website, ML is not even on there.

I already tried reducing Picture Quality when I go too Menu > System Options and that doesn't always work.

So I was wondering if there is some kind of hardware and/or software I could use to have more reliable connection when family members are using up the "bandwidth"?
Please explain in a simple manner because, again, I'm not super familiar with this techy stuff. Thank you so much!