Sad day

Today, I found that my friend deleted me on Internet. I met my friend on this website. We always talked together and had fun. Recently, I need to do an internship in a hotel, so sometimes I couldn't talk with him. Now I've found this things. I don't know why! This thing let It makes me so sad.

Sad Day

Today[,] I have found that my friend has deleted me on Internet from all his social networks accounts. I meet have met this friend (right) on this website. We always talk together Before he deleted me, we would always talk together. And we all have fan would have so much fun. Recently,I need internship in the hotel, so sometime I could't talk with him .  Recently, I have been busy with acquiring my hotel internship, so I haven't been able to talk with him as much as we used to. Found this things ,I don't know why! This thing let me so sad. [unintelligeble, please rephrase]

Your text is quite grammatically flawed. For starters, you should learn about Present Perfect Simple (I have found, my friend has deleted, etc.); you should also learn about the various functions of would, especially when it is used for past repetiveness.

Sad day

Today,I found my friend deleted me on Internet. I met this friend on this website . We always talked together and we all had fun. Recently, I needed an internship in the hotel, so sometimesI could't talk with him. I just found this out, I don't know why! This thing makes me so sad.