I guess that sometimes there can be progress that doesn't feel like progress at times. Assertiveness can be one such thing. Sometimes we can make progress with being more assertive and yet there can be a backlash from that (where others are frustrated with us because we no longer submit to their needs) and that can result in our feeling unhappy about that even though we have made progress. I think there can be a lot of things like that. Change can be uncomfortable to others and (hence?) to ourself. I quite often think that some of those concrete changes can be like that.

Sometimes progress can feel like it isn't progress for other reasons. I guess I'm regressing somewhat right now and so that feels like a step backwards rather than a step forwards. But I guess the step backwards is a step forwards in the sense that it is a necessary step towards real progress.

Sounds like you do think that you are making progress... But that you are struggling a little with some of the ramifications of that. Hang in there. Sounds like genuine progress to me ;-)