The reason you get down voted is because you're not playing at a competitive level yet, you seem to be less than level 30, which is okay, everyone is a noob for some time. But your tactics and playstyle have room to improve quite a bit. Once again, not a bad thing, but try to keep them evolving as fast as you can handle it.
First off, clarity is generally a terrible spell, even on mana-hungry champions, learning to manage your mana and play for kills rather than just spamming abilities is an extremely important aspect of learning to play a tank, as all tanks suffer from high mana costs which punishes them early on. Work on putting more MP5 into your build to get your mana back when you're not using abilities. And trade out clarity for another spell like exhaust or heal for more defensiveness, or ghost for more mobility.
Another thing is trying other supports in lane, while Maokai is certainly a viable support and really is quite good at raking in kills early on, he has a poor transition from early game to mid game if he fails to get at least 3 kills or assists during the lane phase. Other popular supports like Leona or Nami become powerful fight initiators and buff bots mid game, but do so with much less need for gold than Maokai as they scale with their abilities better than he does.
Lastly, Warmog is a poor first item, not because it doesn't make you hard to kill, but because you gain absolutely no utility from it. As a support tank, the best item for you to start out with is usually Shurelya's Reverie, it is a powerful initiating tool and allows you to save allies who are caught off guard. It also allows you to rush GP10, which is key for most supports to transition with. Next up is usually one of the new Kage's lucky pick items. You can sit on a Lucky pick for as long as you like, building other items off the GP10. You want your build to be a mix of damage and utility, it may not seem like it now, but building the right items on Maokai will make his damage increase dramatically. For starting out, since you don't lose a lot of durability through them, look at Sunfire Cape combined with Abyssal Scepter. These two items give a hefty and well balanced chunk of HP, MR, armor, and some damage that fits very nicely in with the rest of Maokai's ability set. Other wise try to work in some more utility through things like Catalyst, which either builds into Rod of Ages which gives more HP and damage. Or something like Ohmwrecker, which is an extremely powerful tower diving and pushing tool.
Otherwise you seem to be doing pretty well with Maokai, remember to have fun with him, and work in advanced techniques as you play him more. Also, some good masteries on him are 0-9-21, taking Mini-Tenacity, Armor and MR, and a little extra movespeed and Mana Regen.