DaemonUmbra

Have you tried making a completely new profile and selecting Forge in that?

Your world's corrupted, I hope you have a backup

Try without Optifine

Please read the "Logs" section of my signature below and provide the appropriate log in the appropriate manner.

I'm asking for the full log of the server, not just the message you see.

No, starting in 1.13 Forge (and mods that use Forge's config system) use .toml files rather than .cfg files, so those .cfg files are probably from an old version

Try deleting Forge's config file

That log does not show a crash, please reproduce the crash then immediately supply the file

All Forge installations add Forge so the launcher sees them as a version of Minecraft, what you're seeing is likely the Profiles/Installations, of which the Forge installer will only ever create one. Also your mods folder is not only accessible through Forge, it's in your game directory (.minecraft by default).

You can use one of the paste sites listed in my signature below or you can try uploading again

setupDecompWorkspace no longer exists in 1.13+, this process now happens when the project is loaded by your IDE of choice

Just make your mod do nothing when it detects a server

Please provide a screenshot of where you are looking in your launcher

Try JarFix

Figure that out on your own, did you? JEI has been updated to fix this btw

This is nowhere near a complete log.

Please read the "Logs" section of my signature below and provide the appropriate log in the appropriate manner.

trans_humanist: Please provide your launcher_log.txt found in .minecraft Xingot: Please do not hijack threads, if you have an issue please make your own.

The instructions in my signature on getting a debug.log out of a Twitch Launcher pack (non-working at this time due to a bug in Mojang's own launcher) explain how to launch a Twitch modpack without their launcher tweaks (Yes this includes doing what Lex said)

Use fewer mods.

1.8.9 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

Please read the "Logs" section of my signature below and provide the appropriate log in the appropriate manner.

As long as you're not on mobile and haven't disabled signatures it's the thing below each and every one of my posts.

I'm not surprised you're running out of memory, what launcher are you using?

Try without Optifine