Mixed

Today is Thursday.
I am learning German now.The problem is,I often mix English with German together.For instance,one day I practised spoken English with my partner,when I mentioned billboard,I say"Pinnboard",and my partner got confused.Sometimes when I went back and talk with Sam,a teacher from Canada,I often say"Ich went……"it drives him crazy.once I wanted to say"Ich habe keine Zeit"instead of "sorry,I dont have time!"Is there anyone who can help me?T^T