Why I am lag playing offline mod

I have just bought Dont starve together and put it in my SSD. My system is Ryzen 5 1600 GTX 1060 3GB DDR4 8gb. I had no problem joining and playing in my friend's server. However, If I create my own server or play in offline mode, i suffer from lag every 5-10 secs. I dont know how this could be happening. Please tell me if there is anyway to fix it. Thank you so much!