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.