ts&p, I have read all this thread and I have found out several things about you - you are a fantastic cook, you have a personal interests (photography) that interests you, despite your own childhood/background you have raised a daughter who is confident and funny (you must be a great mother to have done that), you are willing to work on yourself and your relationship, you are a good friend to other people in RL and on MN.
imo all those things are part of what make you a great person, not the size of your waist or the perfection of your looks.
I once read that what was important was not whether you were extrovert or introvert, confident or doubtful, but rather how you use those aspects of your personality to interact positively with other people. So someone extrovert who is using their personality to involve other people, or to get conversation started is using the attributes positively. Contrast that with the self-centred, over-confident loud-mouth bore who can only talk about themselves...
I guess that when you are at your best, you are a great listener, are empathetic and are interested in other people. Perhaps when you are feeling more self-centred you focus on comparing yourself negatively with others (real or imagined) perfections.
I do think that there is something about counseling (a necessary part of the process) which makes us introspective and focused on our self. For someone who is feeling a lack of confidence it can be a difficult time as you examine that.
It sounds however as though you and your dp want to make things work, and you say you like and love each other, so you will get through this difficult period. And when you do, that will be another thing for you to feel proud about.