I am not able to play the game and i am gonna decay from challenger because of it.

I am in Bulgaria and for the last couple of months my ping has been increasing/decreasing randomly and as of the last few weeks i have been unable to play the game consistently. I get random disconnects, not being able to connect to the game, receiving the queue pop up too late, endless loading into attempting to reconnect to the client into shutdown. Choosing my roles for ranked takes a long time, choosing champions takes a long time and i am prone to simply dodging because i can't pick my champion.

What am i supposed to do to not decay?