Hmm...let's think about what could be at issue.

So first off, One Tamriel introduces some odd combat effects that I don't think have been fully analyzed yet, and these might be partly to blame. What I mean is that the system now tries to "hold" a character steady in terms of dps and taken damage while they level. A wasp that hits you for 1/5th your health at level 15 should also hit you for 1/5th at level 45. I've noticed this can make leveling and dps seem like it underperforms. It also prevents you from going to a zone that's two levels lower to plow through enemies...d'oh. In One Tam, I've found that:

1. It is far more important to keep your armor close to your level. Before OT, it didn't really matter if you were wearing level 30 armor at player level 45. Now under OT that will make you WAY squishy.
2. Likewise, it's important to keep your weapons up to date and close to your level. Their dps output drops massively as you outlevel them.

But let's assume you're wearing armor and weapons that are within five levels of your character level. If this is the case, then some of the following might be to blame for the low damage:

1. Yes, total stamina makes your stamina abilities hit harder, and total magic makes magic abilities not harder. Don't worry about attributes though...they're worth 115 points in their associated resource. Just pile them ALL into your attack resource for that toon and never think about attributes again.

2. Is your gear enchanted? That's a massive pool of resources. Your gear should be enchanted with mostly attack resource (magic or stam) and if you're dying a lot, a few with health.

3. Is your gear the right weight? Light armor helps power magic attacks, medium for stamina. A magplar should probably be wearing 5 light and 2 heavy. A stamblade 5 medium and 2 heavy.

4. Are you unlocking passives? These add up to massive power. You should spend every point in your class lines, weapons lines you use and armor lines you use, as well as class skills. If you are short points, get shards and spend here as a first solution.

5. Are you wearing sets? 5 piece armor sets are MASSIVELY powerful. A lot of this game is about equipping your toon. You have twelve slots on your magplar. He can be wearing two five piece sets and a monster helm set...eventually...not really now since you wouldn't really go get some of that at low level. But at your level you could wear 5 pieces of julianos and 4 seducer, plus a jewelry set you grind from dolmens in a specific zone. If you aren't wearing armor sets, get someone to make you some or do some quick research so you can craft 3-4 trait sets. Then gear up and your dps should boom.

6. What's your jewelry enchanted with? It almost always comes with recovery enchantments. Templars often need to overwrote 2-3 pieces with spell damage enchants...it really helps.

7. Are you using appropriate skills and buffs? ESO is often about incrementally increasing your power via abilities. On a magplar, I have to run entropy (mage guild) on the back bar. This gives you 22 seconds of major sorcery for +20% spell power. On a stam character, you need an ability to buff you with major brutality - rally or shrouded daggers or another skill. Your magplar could also toss out a reflective light attack. In addition to being a good hit, it grants major prophecy, which spikes your crit rating, which gives about 1 hit in 8 50% more power.

8. Are you using the skills as intended? There's a big learning curve in figuring out how to rate your skills to max your performance. If you're just piercing jabbing mobs then it's probably a little slow. On my Templar, I open w entropy for that major sorc buff. Then I toss a few reflective lights, which give me major prophecy and get some DOTs running on the enemies. Then maybe some jabs. When they start getting down to 30% health, I Radient Oppress them to burn then to cinders. That's one rotation for magplars that speed things up.

So...those are some things to consider. But to answer your final question - the 30's is indeed a point in the game where everything feels sluggish. Your characters are tough enough to have complete skills bars, but they have a long way to go. And yes, the moment you hit vet they feel twice as powerful. Then when you have 100 champion points they're twice as powerful as that. Then at 160 with c160 gear, three times as powerful as that. (And don't worry.. it doesn't take THAT long to get to c160. Playing an hour a day, maybe a little over a month.)

If you have specific questions on any of this, feel free to reply here using @davey1107 in the thread so that I get a notification you have questions. Happy to help.