Your mother left you. Your father emotionally abandoned you to more or less take care of his emotional wreck of a wife. That wife was manipulative and treated you like dirt.
The adults were self-absorbed, damaged people who didn't do right by you at all as a kid.
The previous suggestion of counseling is the exact suggestion I would make. I feel like I have some qualification: I was abandoned before birth by my bio-dad as well, due to a mother who is, like yours, very mentally ill and unbearable to coexist with. He left his baby with this abusive, crazy woman because he simply didn't want to deal with her. I met my bio-dad when I was 14 and spent a lot of time wondering how to have a better relationship with him.
V., it took a LONG time in counseling- on my own--for me to get to the point that I wanted to address my issues with my bio dad. I did this when I was 35 and pregnant: we went to counseling together with my own counselor and he pretty much quasi-apologized for how he'd treated me (past and present) then threw up his hands and said that basically, what I get is what I get. It was very, very difficult. I began to see what a victim he saw himself to be. (One example: when they would come into town, I would actually want to know 'when' they might be coming by-- I have waited HOURS at times for them with no phone call--- he finds this 'controlling behavior' on my part.)
It's hard to do this work with a parent, if they are willing. It is indescribably hard and frustrating to hear a parent pawn their faults off on oneself in an attempt to protect themselves. Hard and pathetic at the same time. Very rejecting.
I love my dad. And you know, I now have pretty much ZERO expectations of him. That's what makes it work, frankly. I accept that he doesn't always have much to offer, that I am not a top-ranking priority, and that he's going to consistently disappoint me by still being late and not calling. That said, I also make my effort-- and ONLY the effort I want to make-- in continuing a relationship with him. This is mostly for my son's sake: I think it's important to him that I facilitate *their* relationship, which is by far easier for my dad than being in relationship with me. Kiddo needs a grandpa (and grandma-- my stepmom) whom he can see once in a while.
He's a 'weather talker' too, and so I do understand that frustration. You feel that there are real issues to talk about, and he's hiding behind so much nothing. I've come to realize that this comes from my father's cowardice and fear of being 'real' with me (as well as himself). I am imagining that is also a place that your dad is operating from. Leaving you to deal with a suicidal wife IS cowardly, V.. Something no healthy parent would ever, ever do to their kid. And my guess is that your dad, like mine, would rather not confront his own actions and deal with what went down. Just the sheer enormity of their neglectful inaction is more than they can admit to themselves.
What has happened through counseling is that I have stopped taking on/taking responsibility for my father's disconnection with me or with himself. For example: Sometimes they come into town and do not stop to see us. Three hours drive and no call, no stopping by. I have come to a place where I am no longer hurt by this but expect it as typical behavior from him. This is actually a VERY good place to be in.
Get some counseling and after a long time, then you can decide what exactly you want to do. I did choose the 'take the little he gives me' route, but only after I had worked for quite a while on rebuilding *me* and getting myself to a place where I was healthy enough to deal with the confrontation and rejection which my dad aimed at me during our process with the counselor. That time beforehand was like putting on armor. The blows still hurt, but much less than they would have before. My relationship with the counselor was a healthy one, so we already had a good background where I could go back to her on my own and bounce my impressions/interpretations back off of her and get some clarity. I had a very good counselor who made sure I wasn't further damaged in the process, which is why I do suggest developing your own therapeutic relationship with a counselor or therapist first before entertaining the idea of talking to Dad, if you do. In the meantime, yes, lower your expectations and be glad you have the wisdom to know that he doesn't have much-- if anything-- to offer you. You can also be angry, but DO be glad. Now you know, and after a lifetime of trying to paddle upstream in the relationship, you can rest for a while. You can only be responsible for yourself. Best wishes. It's hard, but if you can invest in yourself, your other relationships and self-perceptions will be so much the better for it.