Sachi and co. death's were probably the only deaths, and if you cried for when Sachi's message came you're probably just like me.
After that (if I remember correctly) is only 1 death, but hear me, ''death'', it all comes good.
There are a couple of episodes of just happiness, nothing sad.
It also gets really sad later on but without deaths, and yes again it all comes good in the end.
And if you cried for something like Sachi's death you really shouldn't watch Clannad and the Clannad Afterstory, you'll be crying a river and you will probably end up depressed.