Need some advice regarding head dropping/ pulling

Many of you may or may not be familiar with the epic battles I have had with my horse Tally over the last year or so. I won't go into it all again, but suffice to say that I have finally gotten her back to the point where I can get on her and ride her without a huge to-do over everything. Yesterday I got on her, and I've seen this behavior before, but I wanted to check and make sure it's what I think it is.

The whole time I was on her (which wasn't long, because I'm trying to keep our rides positive right now-- VERY positive) she was dropping her head and pulling on the reins, despite me slackening and slackening them and pushing her forward through it. She wasn't spooky under saddle, so I didn't have a problem letting them out. She was difficult to bend to the right, though she bent to the left just fine, she seemed to be bracing against the rein on the right. She was a little harder to stop than normal, and when I did stop and ask her to back up she took very small steps, then stopped completely and pawed.

Her teeth were floated in July and the saddle is fitted, she doesn't seem to be lame or moving stiffly on the ground/ in hand. I'm pretty sure I know what this is, but I wanted to get some more objective opinions and some backup before I try to "fix" it. Thanks in advance.

The pawing can be two different things: nervousness (displaced behavior) or frustration. The fact that she was harder to stop would lead me to believe she was unsure of something, or she was in pain thus creating the slight impulsive behavior. However she could have been frustrated with what was being asked of her because she COULDN'T do something you were asking (due to physical reasons), she was confused, she was bored, etc. Without seeing it, it's hard to say why she was doing these behaviors.

Jester is also stiff on his right side, it was hell during pole bending because he wanted to stiffen and keep running.

I just kept stretching him and he showed nice improvement. However, I'm not entirely sure how to fix the stopping thing. I personally would try jiggling the reins gently from hand to hand and then gradually build up the force until she obeys. Works on certain things for stop and back-up.

Sounds like she's leaning on you. Alot. My mare does this all the time. She bears down and runs all over me. Don't give more slack, if you have a long rein already. You need to give half halts to adjust your horse and rebalance her. I have to do alot of half halts with my mare to pick her up and get her off the front end. Some horses are just quirky. It may take a while to figure out what will make her lighten up. Is she lazy all around, or does she just lean???