Loss streaks and the "Take a break advice"

All anyone ever says in regards to the topic of loss streaks is, "take a break".

But that doesn't work when you come back night after night with no wins. Day 1: 3 losses in a row, Day 2: 3 losses in a row, Day 3: 3 losses in a row.

My biggest loss streak is 12 but I've had up to 8 or 9 many times.

This has only been in the past few weeks though, ever since I hit Diamond 3. Now I'm about to de-rank into gold.

I play entirely solo queue and the first few months were fine. About 50/50 win and loss. Now I'm at about 75% loss percentage.

I've been playing consistently almost every night since release, so either something happened with matchmaking, or I got way worse and everyone else got way better at the game out of nowhere and for no reason.