lots of server lag!

Hi! I recently started a modded server for 1.15.2 forge. The only mods we have are Abnormals Core, Betteranimalsplus, BiomesOPlenty, Fairylights, and Timber. I already deleted several other mods to make the server less laggy. The issue is that we often cannot eat. We eat but it doesn't go through. We also have to break a block twice for it to break which you can imagine is very frustrating. Its also very difficult to kill mobs because its so laggy. I was wondering why this is because I have seen others with over 20 mods whos server runs a lot better than this. Thank you!