I'm not qualified to give advice but I've certainly fallen into the codependent category myself in the past. Often without realizing it's happening and then when I'm established in that role, it's really hard to get out of.

In the past I've often suddenly snapped out of such a state which is always painful as usually leads to anger or abandonment. If it's a valued relationship and you feel the other person will change then perhaps take some gradual steps towards being more assertive and doing things for yourself and asking for what you need. Then, depending on the response you get, you can decide if it's worth fighting for.

This article is really good and is one of the ones I read today before posting. It seems to suggest that a codependent could also be an inverted narcissist if they exclusively seek out narcissistic partners and are unable to function in relationships with non narcissists.