I don't believe sugar is addictive - you are obviously getting a 'hit' from it though. Your blood sugar level goes up very quickly giving you energy, then it comes crashing down making you tired. You then want something sweet again.
I always want sugary food when I'm tired.
Eat wholemeal carbs or nuts and seeds instead, which prolong and steady your blood sugar levels. Cut down on sugar and your body will adjust. The more sweet things you have the more desensitized you are to the taste - making you tolerate it more.
If you cut it down, hopefully you won't like it too sweet eventually ...