1.12.2 modded server lag

[BigBoiMans]

So me and my friend have been wanting to update to 1.12.2 from 1.7.10 for our modded Minecraft server. This server is what some people would call over modded but it worked perfectly fine for 1.7.10 but for 1.12.2 was not the case. We got 120 something mods installed in the beginning but its now down to like 60 because the lag was unbearably bad because of the amount of chunks rendering. I'm almost certain its a problem with the 1.12.2 server because when I added any mods with blocks to load in chunks it would jump up to 78 avg tik when flying and just starting it up but I still am not for sure. Btw its running on the recommended version the latest did the same thing as well. 4G of ram for the server (honestly a lot but it'll be fine) 6G for the player on Minecraft launcher. If anyone has any input it would be greatly appreciated because I've been on this for hours now. (Pic was taken without the player in the server.)

Edited June 3, 2021 by BigBoiMans