HELP | Instagramers |My ACCOUNT is STUCK

I’m owner of Instagram account with 36k organic followers. I made it 2016 and one year I reached 36k. 3 years I stand on the same number of followers. My instagram account is kinda ‘dead’ - low activity etc...
Some of my pictures are gone VIRAL - up to 600.000 reach, 30.000 engagement ...
Also, on the story posts I have reached 50.000 per one story, now that number is 500...
I have pretty good username but I don’t know what to do to grow up my account. Should I buy followers, buy likes or just to allow Instagram algorithm to push me viral??????
Help me. Thank you

never once try to buy fake followers or likes
accounts that have been left of course will decrease its activities, especially its engangement
therefore there is a need to start over again, such as researching good content and encouraging followers to interact, don't forget to research specific hashtags. for me the use of Hastagh is very important with the current algorithm

what's you niche? Is there a time when your account remained inactive for a while?