You'll run into levels like this as heals that just drag, all specs get this but heals seems more susceptible
I used 4x until I got the next 2 guys and then swapped between them.
1. Hotkey 4-X's Flameguard ability and pull with that and use it whenever it's on cool down. It does good damage and buffs his Defense so you can spend more time on dps
2. For most fights keep 4-X in dps mode, he'll still hold threat and he'll dps a ton more, switch him to tank for boss fights.
3. Keep 4-X geared. If you aren't cybertech, make friends with one. He is either awesome with good gear or poo with average, not very forgiving.
4. Once I got a better hang of all this I'd do all but boss fights with incendiary cell active for the extra dps.
If all else fails, go back to Tatooine and re-do quests or do quests like the bonus series if you skipped them to get you over the hump.
This is what you have to do.
I sat in the queue for nearly two hours this morning, and when I found a group someone was afk and didn't join so it never happened... I guess that is mostly because I play at such odd hours, but I have also experienced the same leveling up problems that you mentioned.
Best of luck leveling, I went from 27-31 today (and still playing) using the above method (with some PvP and Flashpoints thrown in because I enjoy those).