Is it normal that all my troops disappear?

Solution 1:

Yes that is normal.

If you drop troops in a battle they won't be sent back to your Army Camp, even if they are still alive when you win.

There is an exception to this - Heroes. They will return back to your base once the battle is finished.

Solution 2:

Whenever you attack, any troop(s) that you deploy will be lost (you will not get them back after the battle), regardless of it they survive or not (even if they don't take any damage). This also applies to spells that you use - you must replace each spell you place. The exception to this are your Heroes (Barbarian King and Archer Queen), which must simply rest for a period of time after a battle.

On the CoC Wiki's Game Tips page, it is tip number 5 under 'Offensive Tips': "Once you deploy a troop during attack it must be replaced, even if it survives the battle. This discourages players from attacking with more troops than necessary to achieve their objectives. The only exception to this is Heroes."

Source: http://clashofclans.wikia.com/wiki/Game_Tips

Solution 3:

Yes, it is normal. Unlike games like Boom Beach and Castle Clash, when you deploy any regular troop (not Heroes, but includes Clan Castle troops). It will disappear from you army camps, even if it survives the battle.