So I run Minecraft, and the launcher opens. I tried using 1.9, 1.9.1, and 1.9.2, and when I click Play, everything runs and downloads and then Minecraft starts. I then try to open a World that I've played on before on 1.8.9, and then it says Downloading Terrain... and then opens the world only for a second or two (or sometimes not at all), with no terrain or anything, and then closes, and I get this report:
[23:25:55] [Client thread/INFO]: Setting user: JayParish
[23:25:56] [Client thread/INFO]: LWJGL Version: 2.9.4
[23:25:57] [Client thread/INFO]: Reloading ResourceManager: Default
[23:25:58] [Sound Library Loader/INFO]: Starting up SoundSystem...
[23:25:58] [Thread-5/INFO]: Initializing LWJGL OpenAL
[23:25:58] [Thread-5/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[23:25:58] [Thread-5/INFO]: OpenAL initialized.
[23:25:59] [Sound Library Loader/INFO]: Sound engine started
[23:26:00] [Client thread/INFO]: Created: 1024x512 textures-atlas
[23:26:44] [Server thread/INFO]: Starting integrated minecraft server version 1.9.2
[23:26:44] [Server thread/INFO]: Generating keypair
[23:26:45] [Server thread/INFO]: Preparing start region for level 0
[23:26:46] [Server thread/INFO]: Preparing spawn area: 4%
[23:26:47] [Server thread/INFO]: Preparing spawn area: 9%
[23:26:49] [Server thread/INFO]: Preparing spawn area: 14%
[23:26:50] [Server thread/INFO]: Preparing spawn area: 21%
[23:26:51] [Server thread/INFO]: Preparing spawn area: 29%
[23:26:52] [Server thread/INFO]: Preparing spawn area: 38%
[23:26:53] [Server thread/INFO]: Preparing spawn area: 48%
[23:26:54] [Server thread/INFO]: Preparing spawn area: 57%
[23:26:55] [Server thread/INFO]: Preparing spawn area: 67%
[23:26:56] [Server thread/INFO]: Preparing spawn area: 75%
[23:26:57] [Server thread/INFO]: Preparing spawn area: 85%
[23:26:58] [Server thread/INFO]: Preparing spawn area: 95%
[23:26:58] [Server thread/INFO]: Changing view distance to 9, from 10
[23:26:59] [Server thread/INFO]: JayParish[local:E:3d2c2147] logged in with entity id 616 at (-122.5, 70.0, 246.5)
[23:26:59] [Server thread/INFO]: JayParish joined the game
[23:27:03] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4725ms behind, skipping 94 tick(s)
#

1. A fatal error has been detected by the Java Runtime Environment:
   #
2. EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffeb40a6b87, pid=10696, tid=3812
   #
3. JRE version: Java(TM) SE Runtime Environment (8.0_77-b03) (build 1.8.0_77-b03)
4. Java VM: Java HotSpot(TM) 64-Bit Server VM (25.77-b03 mixed mode windows-amd64 compressed oops)
5. Problematic frame:
6. C [ig8icd64.dll+0x16b87]
   #
7. Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
   #
8. An error report file with more information is saved as:
9. C:\Users\macsm\AppData\Roaming\.minecraft\hs_err_pid10696.log
   #
10. If you would like to submit a bug report, please visit:
11. http://bugreport.java.com/bugreport/crash.jsp
12. The crash happened outside the Java Virtual Machine in native code.
13. See problematic frame for where to report the bug.
    #
    AL lib: (EE) alc_cleanup: 1 device not closed
    Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release

This kept happening over and over, so I tried deleting .minecraft and the minecraft launcher, and re-downloaded everything. And it kept happening. Please help as soon as you can, thank you so much!