A love triangle of sorts...

I'm in my early twenties, currently in a five year relationship with a guy who is absolutely lovely to me, he has been there for me through all kinds of hell (throughout people dying, my chemotherapy treatment etc etc) but in the past year he seems to be more interested in his friends (even outrightly putting a female friend first) and seems more interested in sexual activity than actually having deep conversations and romantic notions as we used to. He says he is sorry and will change, but then we continue to argue and I feel smothered, like I've lost my independence. This sounds terrible, but I have recently started crushing on two other people. I have no intention of cheating or anything like that, but I feel as though it's opened my eyes to what I am missing in my own relationship. First -I have always loved my best friend whom has known me longer, and I have always ignored my feelings for him as we've been with other people, various denial reasons etc; we are compatible and have more in common but I am scared of being around him recently in case my feelings get stronger for him - we have the same life goals whereas my current partner does not want to travel or do the same things as I do. But I can't bear the thought of being without my current partner, I'm so comfortable with him and cannot imagine how painful things would be without him. He's done everything for me, but I just do not feel physically attracted to him anymore - however I still want to give him the world. I don't want to change him - but I feel like if I leave I will regret the decision and then have lost him forever. But then I would never know how things could be with my friend. So I feel like it's a lose/lose situation. Second - there is another guy who seems compatible, who has recently shown interest - I thought it would be nice to just get to know him as a friend to see what his personality is like but since he found out I have a boyfriend it seems he is embarrassed having asked for my number, and has no interest in being friends despite my efforts. He seems like he has the same drive as me, and similar life goals, but I can't make a better judgement as I barely know him. I know this is pretty long but even just a small piece of feedback would be appreciated, your advice is the best I've found! Thank you for your time!!!!

so I'm a blunt fish, and this will be a blunt message. K.I.S.S. Keep it simple stupid. No offense. But anyone and everyone can and does complicate the emotion of "love." The best way to combat complicating this emotion is to set "laws" within yourself that your going to follow unceasingly and without reserve. My personal law surrounds "loyalty and sticking to my word." I believe so long as one is loyal and I have no proof of disloyalty then I will stay cause really what I am after is a true best friend that can understand ups and downs success and failures, yet stick with me throughout my entire life. If you got with your bf because of looks then I would tell you to expect the same results to happen in your future relationships. Your best friend is your friend, since you differentiate between bf and friend make sure there is fine line that both parties understand clearly. As for the other guy, he's a good man. He should care whether or not you have a bf and be very cautious. It means he's thinkin about what it would be like in turn to have another guy talking to a gf of his. Simply following the law of loyalty, loyalty between another couple in my opinion. This is my opinion, ps keep in mind that this only focuses towards an individual who is looking for their "special one" and not in the phase of their lives of "just looking." Hope it helps