Tell us what possible new evidence you can collect in next three months in addition to recomendation letters?
If you want to respond to RFE, you need
1): several independent letters
2): Try to find the independent review paper citing your work and amplify it.
3): You probably did not present your submitted evidence well. You may need to readdress them again in your new petition letters
4): any possible new manuscript, conference abstract, any email consultation from your peers, anybody of any organizations ask you contribute a conference or to join a professional association, etc.
Just a genral suugestion. Hope it helps.
If you wanna discuss further, email me yjy_wang@yahoo.com
Good luck.