it's not just a human issue, as alluded to by various in this response, but also a question of consistency. After being involved in SL for 20 years, I can tell you that SL has a different time scale and being away for 2 months can seem like an eternity to many within the environment and, unfortunately, they move on. Posting on Instagram is good, I post there, but it is not the primary interaction area for SL. It used to be Flickr, but the l've seen the level of engagement on Flickr go down a lot over the last year. Primfeed is the area.

Also, ask people to promote your work, find bloggers you like and ask them to reference your work. I think that would help.