Okay so, when I join a SINGLEPLAYER world with forge my fps is fine, I don't lag and my frames don't freeze. BUT when I join a SERVER with forge my frames freeze, and my fps goes down rapidly down then back to 60 then back to 1 (my common fps is 60-90). The mods I'm using are:
Orange Marsh's animations
Orange Marsh's HUD
5Zig
Optifine
Autotip
Keystrokes mod