I have just gotten a new laptop with Windows 10 on it, and for some reason, whenever I try to go on a singleplayer world, I get stuck on the loading screen. It doesn't load the singleplayer world, no matter what, however, my PC does not tell me that it's "not responding". I've tried tons of things, from repeatedly trying to open the world with no avail, to just waiting thinking it would load eventually (I have a pretty powerful laptop, so this is probably not the case), to removing the .minecraft folder entirely and starting a new one, to even uninstalling Minecraft altogether and re-installing it, all without success. Trying to join a server loads the world for a few seconds before the game immediately freezes. Sometimes, I can't even get to the main menu screen - the game sometimes just halts on the Mojang logo loading screen. However, this only happens with the new launcher - the old one that still uses Java does not have any of these problems. I need help with this because when using the old launcher, I keep accidentally clicking on the thing that lets you download the new launcher, meaning that my recycle bin is full of Minecraft installers.
I don't know if this is of any use in information, but when using Forge, I found myself getting stuck on the Mojang screen much more often, more specifically on the screen where the mods are being initialized. This bug, however, cannot be the fault of the mods, as I have tried numerous times with clean .minecraft folders and even un- and re-installed Minecraft without modding it just to see if that could fix it.

Thank you for your time and I hope to hear from you soon.