If you know any thing that can help me please let me know.

Have you tried any of steemchiller's APIs?

https://sds.steemworld.org/transfers_api

There should be something here that'll be easy to use and reliable. It won't broadcast but it's quicker than Steemit's APIs for retrieving data.

I think I’ll need at least 100+ active participants per day

I'm not convinced there are that many engaged users on the platform, let alone enough to be willing to risk their STEEM on a lottery.