Hey Jaymie,
Check out [post|446185], [https://www.reddit.com/r/mobilerepair/comments/7bifmf/iphone_7_boot_loop_after_screen_repair_no/|this one], as well as [https://www.ikream.com/2018/02/apple-iphone-7-plus-stuck-apple-logo-infinite-boot-loops-troubleshooting-guide-25249|that one]. It sounds like some components may have become severely damaged from the fall. In both of the above cases, broken flex cables were the issues. Often, accidentally putting the short screw in the long hole or the long screw in the short hole cause damage to the logic board when installing new components. I would inspect the logic board closely to make sure no physical damage occured when the phone was dropped. In addition, I would check to rule out the potential screw problem, though it sounds unlikely in your case. If there is damage to the logic board, I would look into learning microsoldering, or contacting a company like [http://mendonipadrehab.com/|iPad Rehab]. They specialize in board level repairs on iPads & iPhones.
If you are interested in microsoldering, watch [https://www.youtube.com/playlist?list=PL4INaL5vWobD_CltiZXr7K46oJ33KvwBt|these videos], or [https://www.youtube.com/channel/UCPjp41qeXe1o_lp1US9TpWA|these ones]. Also, check out [guide|61535|this guide].
Hope this helps,
-Tanner