First of all, my background:

Im 27, i work as a senior software/infrastructure engineer with mostly gaming background.

I've been playing dota 2 since 2012 on and off and wc3 dota before that

Somewhere around 2013/2014 when mmr was first revealed i was sitting at 4500 mmr which at the time was a big deal and enabled me to play in inhouse leagues like c9dl, IXDL, dotabro, JDL and etc
Because i was a poor fuck back then with financial issues i sold my account for 50 bucks and stopped playing for a while.

Since then i played on and off on different accounts borrowed from friends that were mostly in high archon/low divine range so last year i decided to make a new account, recalibrate properly and start from scratch.

Im pretty PMA, i dont tilt or flame, if i have a problem i just report/avoid and move on.

I calibrated at legend 2 and almost instantly dropped to archon and in couple of months time i dropped to crusader 5.

I play pos 1, 3 and 5 with a small pool of mostly meta heroes and in the year i played on this account i noticed and confirmed a pattern, where i would win, start climbing and then drop almost always exactly where i started and then some more before i could win consistently again, which in turn lead to a negative win rate and a slow downwards drop.

At this point my high mmr friends start jokingly flaming me so i decide to take some paid coaching sessions.

I hire 2 different coaches and go trough replays and live games in both won and lost games.
The results of coaching:

• Both of them conclude that my personal gameplay as pos 1 is fine and besides some minor macro decisions like helping my support/team when i should be farming and sometimes prioritizing jungle creeps over lane creeps there really isnt much wrong and i should be reliably climbing to mid legend.

• Both of them also conclude that in most of the games i lose which are usually in lose streaks there is at least 1 smurf(usually mid) in enemy team way above our mmr and a griefer or 2 on my team(usually pos 5 and 3)

• Both of them see the same pattern as i do, where i stomp couple of games in a row with a really high KDA and then lose the same number of the games in a row + some.

We conclude that the game has probably flagged me as a smurf/booster since i have less then 1000 games and have been stomping games.
Now with newly found knowledge from those sessions i end up stomping even more and the same pattern continues with now mandatory lose streaks after the stomps that continously drop me lower and lower, the lowest point being matched with guardian players.

At this point i decide to do a little experiment and bet my friend who is a divine mid player that he cant climb out since he is flaming me and we agree that he plays 100 games on my account to see if he can climb out to archon.

At the same time i find myself a legend 3 account online with more then a 1000 games, 10k behavior and in pretty good standing and buy it.

We both start playing and the following happens:

• He played around 50 games on my account in a week, climbs to crusader 5, couple of games away from archon and in the same manner as myself, drops down even lower from where he started, he quits playing.
• I play for a week on my new legend 3 account and stomp my way to legend 5/ancient 1 and then the same exact pattern happens, i go on a huge lose streak back to legend 3 and then some more all the way to legend 2
• A good number of lost games on my new legend account, the games are straight up stomps where at least one of the players in my team is straight up griefing and feeding.
  The chat seemingly doesnt work as if i am muted(nobody responds to questions, pings ,suggestions etc), post game chat also doesn't work. Behavior score is varied and queue time is around 7 minutes on average

Since i know you guys are going to ask for dotabuff which i dont have enabled for overwolf reasons here is the most recent game i played 6525421268
And here are some screenshots https://imgur.com/a/UlFVp0J

So now, my question is how the fuck do i even play this game?

If i make a new account, im just gonna be flagged as smurf again.

if i buy a new legend account i am either going to stomp and be flagged again or if i buy a higher mmr account i am just gonna feed due to the skill difference as i really suspect i am going to be able to play in ancient or divine comfortably.

Any advice?