Coming back to modding

Maybe two years ago now I made a functional, about 200-long modded setup. Recently I've decided to look at playing the thing again, but it no longer correctly launches.

I'm here to ask what I might have changed over time to make the pack unable to function.

The error appears due to memory management issues: at a certain point, the program's CPU use drops to basically 0 (fluctuating between 0% and .5% system capacity from around 30%), while memory use remains constant. This continues until, some time later, the thing crashes. The game window is a Mojang loading screen with no additions.* 

That's running the game off of the most current 1.7.10 version (10.13.4.1558).

Running with the Forge version I previously used, 10.13.4.1448, the same symptoms occur.

This setup had between 5 and 15 hours of game time when I first made it, without any crashes of this sort (past creation, of course, when I had to iron out item ID conflicts and all that).

Error message (appears after crash as popup on MC launcher):

*An odd thing is that, when I first was launching the pack, I would have a forge logo on the bottom right, animated, as well as a varying set of progress bars. These no longer appear: when they did, the step at which this slowing down would occur was (I think) 4 of 7, it is a step where all mods are loaded in alphabetical order, but not the first time. The first mods would load rapidly, but by about 160 of 208 the rate of mod processing would be about 0.

After running through the crash several times and cross-referencing the error logs, all logs end on the same lines:

Thanks for reading, help would be appreciated, though even without I'll probably muddle through. More slowly, though. Right now I'm thinking of starting by removing a bunch of the mods from this, see if that helps. If not, I'll look at running it with different launchers (my legacy FTB launcher has a command pane I can check for errors), and maybe brush up on what the coremods are and do.