Just play without the resource pack or with a lower resolution one, as the highest the resolution, the lower the game's performance. If you could upload a video showing how the resource pack affects the game performance, it would help a lot.
I suppose you are refering to the former Windows 10 Edition. In that case, try hard-closing Minecraft from the Task Manager (Ctrl+Alt+Supr and then click on Task Manager) if it is open, and then try re-opening the game. If your problem persists, try reinstalling Minecraft from the Microsoft Store.
Suggestions may be sent on the Feedback Section onĀ minecraft.net. Mojira is only used for bug tracking.
I thought I was a problem of my computer. Huh.