I love using poisons too but vanilla is severely lacking in this area. After about level 3 they are worthless and you can reach level 3 before you even get to Riverside.
Here is a great work around if you are willing to put in some work. This method also requires you to use self control or you can easily break the game.
1 - Get a Fortify Enchanting mod and learn that enchantment.
2 - Now use the restoration glitch to make more powerful enchantments and make a lot of fortify enchantment cloths with lots of different strengths.
3 - Now use the fortify enchanting cloths to make fortify enchanting Alchemy cloths of lots of different strengths.
4 - These fortify Alchemy cloths will let you make poisons of much better strength than vanilla. You will now actually be able to kill something without needing to use about 30 poisons.
5 - Check out the newly added Stinger-Poisoner mod for a fantastic lingering poison enchantment.
This is not as good as a mod that makes poisons worth using but I actually find this much better so I can customize my own poisons to fit the level I am at as I level up. I also use an enemy scaling mod so my enemies are always much stronger too. This makes using poisons a total blast in this game. Good luck!