What strikes me most about this question is your comment about your age. You state that you feel more 17 than 43. This is often a sign of a developmental difficulty. As we develop we go through certain stages; at 17 we learn about our identity and shortly thereafter, about love and relationships. Those ages of 17-25 are so often a difficult and tumultuous time. It seems you are still feeling them, expressing them in a love relationship that also may also feel stuck or at least not fully resolved.
There is great hope here however! I so liked to see clients with this type of issue as one on one cognitive therapy can help much to get you past the "stuck" period and onto a better life. Another thought: The depression may be what you always felt, covered over by behaviors that were not as functional as you would have liked. Now that you are working to resolve your issues you are feeling the feelings directly. Take heart as so many times this is what folks feel prior to a major breakthrough.
Seek out a good therapist, one who looks at both your thoughts and development. Know that you have to find your own identity before relationships with others will work out well. It will not be easy, and you may find yourself feeling some very powerful things but it will be worth it. Medications alone will not solve this type of issue.
The alcohol issues are important but do not minimize the experiences of your earlier development. Only by dealing with those issues will you find your self moving forward.