lvl 70 warrior tankFollow

You're probably just expecting too much. Quite an annoyance (at 80) is fresh tanks trying to run "like the big guys", pulling way too much, way too fast, and in general resulting in suck erratic "tanking" that it's more than just slightly irritating for everyone else.

For one thing, you really need to give your gear a chance to catch up. Those pieces you got are decent, but there will be better ones just from doing the quests leading to the instances.

More important though, a healer actually having to sit down and drink is... well... NORMAL. Just what makes you think that YOU are the reason for it? The healer might totally suck and spam heal, be undergeared, or both. Maybe your dps is taking way too much of his attention because they just don't know any discipline. After all they're likely to be playing a level 80 toon and are used to just nuking everything to pieces, expecting the epic tank to hold all the mobs...

Seriously... just keep doing what you're doing and don't question your own abilities too much before making absolutely sure that everyone else is doing exactly what they're supposed to be doing. Get 2/2 Confidence and 5/5 Attitude with 5/5 Awareness and you'll be an excellent tank. For everything else... there are open seats at the bar and I think we got some peanuts too...