I tried Sion support and this is how I felt
I'm just kidding it was ok i guess....
I'm just kidding it was ok i guess....
Sion support in the everyman's hands is nothing more than a butter knife
Sion support in a Sion main's hands is Excalibur
But I'm a Sion main 
Y'know, it's your first time. It can be hard to adjust. It took me a while to get used to top and jungle Sion, since I started out exclusively playing him as a support (I was a support main when he got reworked, and it just fit for me).
I played him twice.

Sion, is there any role he can't fulfill?
Bot carry is probably the hardest to pull off, but he can still do it with a competent support.
You should have gotten
for the

Don't you dare accuse me of not buying sightstone on supports.
You just have to learn how to bowl without pushing the lane. When you get rank 3 E and start chunking the enemies for 1/4 of their health every 10-ish seconds...
https://media.giphy.com/media/GazPMD1iWfgcM/giphy.gif
Focus on poking the enemy down with your E without pushing the lane and wait for the opportune moment to set up your Q. The most important skill to learn as support Sion (even more important that when you're in other lanes) is to be effective without pushing your lane.
You can poke all the time with E, but if you throw minions through the wave, you're going to push real quick. You can get knock-ups with your Q for good trades, but you'll end up pushing again if you don't choose the right spot. You can use your shield to go in for a trade or set something up, but if it pops, you're pushing the lane as well.
The support playstyle and mindset is just a lot different than lane or jungle Sion.
Well I didn't even max my E. However, to be honest it actually was pretty good, I was just talking shit about it for the memes.
Yeah, I personally prefer maxing E first, but I know a bunch of people go for Q first like in top lane. I just find more opportunities to use E than Q during laning phase, so the reduced cooldown, huge damage increase, and increased slow when you max E is more appealing to me than the reduced cooldown and damage increase on Q.
E tends to be more reliable as a damage/CC source than Q, since it doesn't require enemies to sit around in one area for 2 seconds. Especially in bot lane, there are lots of supports and a few ADC's who can cancel your Q pretty easily, too, so investing in it early doesn't reap all the benefits.
Sorry, I like to talk about support Sion a little too much...
Nah man I'm learning from this [slayer-jinx-wink] The reason I don't like maxing E is because spamming it makes you go oom fast, but maybe support is a different story. In top I typically use in not as a poking tool but only as a slow for my Q.
Yeah, it's a lot different for top lane. Playing support, I tend to not use my shield much unless there's an opportunity to all-in the enemy or I have to use it to escape/body-block for the ADC. As opposed to top lane where you want to use it any time you trade. That makes a big difference in mana usage and lets you use E much more freely.
And, having to really set up for good shots that won't push your lane can take a little time, so you usually won't be full-on spamming it. I very rarely go oom in lane, and it's usually just because I stay in lane for so long before backing.
It's actually really funny in the early levels - when you're matched up against mage or enchanter supports, you can push them to oom themselves pretty easily! Your E does pretty decent damage and is a little provocative (they're getting slapped with their own minions), so they feel pressured to poke you back. However, their poke usually costs more mana, so they end up running low pretty quick. While you, on the other hand, still have 75% mana!
If you do end up with mana problems, grab a
. CDR, armor, and mana for a cheap price! I usually build it into
, which really solidifies you in your role as the "CC Wall".
I'm a W man myself. I like the whole "you can't kill me, but by maxing my defense I somehow am dealing more damage also"-thing.
When I started playing Sion I was a W person, but eventually I learned that I could bully better with Q. If you're not confident that you will win lane I guess you could max W, but I almost always think Q works better.
What runepage/masteries did you go for? Because they matter a lot. Ya know, beyond playstyle.
When playing Sion support I generally go mage Sion, personally. I still build full tank but my runes are ability power based with magic pen or hybrid reds, ability power quints, ability power blues and choice yellows (health per level if you want to be greedy and know you can get away with it)
Sion support is good, as long as your aren't picking him into cc heavy enemy.