Daddy issues and going about healthy relationships/confused about sexuality.

I don't even know if this is the right subreddit to post him because I'm not even sure if I'm gay. I'm a 17 year old male and ever since I was a little kid I remember wanting to get close to older men in my life (usually school teachers). It wasn't super significant when I was younger and wasn't something I spent time thinking about until I was a sophomore in high school and got pretty close to a teacher I had. Our school had a rock climbing club and he used to drive me every week to go rock climbing with the people in the club. I got really emotionally attached to him very quickly. I remember on the way to the rock climbing place I told him one day how I saw him as a father figure, and he didn't understand that because my biological father is present in my life and he didn't think he earned that title, but to me he had made a bigger impact in my life than anyone else ever has. He saw himself as like a mentor to me and I didn't really push the "father figure" thing again explicitly but I think every time we interact he's aware of that, if that makes sense.I was somewhat close to my dad as a little kid but as I got older we became very different and we don't really do anything anymore. About a year ago I found out my dad was cheating on my mom with prostitutes which made me pretty and uncomfortable and made me dislike him pretty strongly. He lied and said he didn't even though I had evidence (internet history) and convinced my mom I was a liar and a manipulator and worsened our relationship as well. I barely talk to my dad unless I need to but I'm cordial.Prior to my relationship with that teacher, lets call him David, I always thought I was straight and never had a moment of questioning my sexuality. I hit puberty pretty late probably about a year ago, and I should be thinking about sex all the time, relationships, and things like that. I find myself spending a lot of time thinking about my relationship with David and how to get closer to him now that I'm no longer in his class - not in a sexual way at all - more of a "I wish we could do more things together (like hobbies)". Although I don't have sexual thoughts about David, I do watch gay "dad/boy" porn with the dads resembling that teacher - all taller, muscular, lumberjack looking dudes. I've never had a sexual experience with a man but I have with women and found that fun and fulfilling.I started to question my sexuality largely because my mom thinks it's weird how close I am to David and how much he means to me. I don't know if a straight 17 year old dude would be so fixated on a relationship with a man that is like a father to him. I feel like in general seeking a father figure is something that usually straight females do. I don't think any of my male friends would pursue a relationship with an older man in the way that I have. I haven't ever pursued a relationship w a female aside from hooking up w girls (sex, lol) and it was cool. To be honest tho, I would much rather spend the rest of my life with David than I would with any girl I've ever met.I'm not sure if I want to have sex with older men but I wish I could meet a man that could be like a surrogate father figure, as weird as that sounds. It just sucks and makes me sad because I know that it is unrealistic for a person to fulfill that role. I think about perhaps pursuing a relationship with an older man but I feel weird about sexualizing the role of a parent. My relationship with David has been the most meaningful experience in my life because as we've gotten to know each other through the years I feel like he's more and more of a father figure I really wish I had. He used to not be super outwardly affectionate and now after every time we have lunch together or do something he gives me a hug, something he used to joke about not doing.I'm really really confused and feel kinda hopeless. Another issue with pursuing a platonic father figure like David is I find myself wanting the relationship to be way more emotionally intimate than it probably would be in most father son relationships (long hugs, saying I love you frequently, etc.). I also don't know if physical and sexual attraction are two separate things but I don't find myself wanting to do sexual things with David but being close to him physically is incredibly appealing to me. I fantasize every day about being his son and bonding with him and the time we spend together is probably the biggest source of happiness in my life. I don't know if (when I turn 18) try and develop sexual relationships with older men in hopes of these men being father figures to me. I'm not super interested in sex with men despite watching gay porn, but I feel like I would have to have sex with these older men so that they could fulfill (or try to fulfill) my desire of having a caring, loving, nurturing, and protective dad.It makes me really sad because I feel like there's no solution to the way I feel. I wish I could develop a really intimate relationship with a man that I can look up to as a father and spend significant time with him without the pressure of having sex. Fathers don't have sex with their kids (ideally) and I wish I could have a genuine father son relationship with a man but I know that doesn't ever happen or work out. Any advice is very much appreciated.TLDR: I'm a 17 year old male with issues w my bio father and I get really emotionally attached to father figures in my life. I am confused about my sexuality and I know if I were to be in a gay relationship I would want my partner to be a surrogate father, and I don't think that's healthy nor is it a fair expectation to hold to a romantic partner.