Alternative to firebase

I am trying to get my realtime app converted to firebase, all good so far except bandwidth consumption. I have a dataset under 100 megs that I need to refresh every few minutes, this means that none of the plans will work save for the big fat $xxxxx enterprise plan, which is something I wouldn't commit to even if i could.

So I am hoping to find a replacement I can host on my own, i am running a bunch of ec2 instances at AWS along with redis, memcache and so on.

Something I could just plug in and change the endpoint, pretty much how slanger works en lieu of Pusher...

Does anyone have any ideas? Don't mind getting my hands very dirty.

TIA