I mean keeping the interest level high for 4 years, is that even possible? Never been in a long term relationship, so I have zero experience with that
I've been in a few very long term relationships, and I can't pretend to know any secrets. But from my experience (not only in my relationships but from observing others), the woman has to form some sort of emotional connection to you that she finds valuable, and thinks would be hard to replace. Now how you get her to form this connection, I'm not sure.
I know a lot of guys here say all girls are the same, there are no good girls, and such. But I have found, for me at least, a woman with more old fashioned, traditional values is a far better bet for a LTR. I say for me, because those are my values as well, so it's a better match for me. I know another couple that has been together a long time who have both had troubles with addiction, but have overcome them for the most part, and maybe that is what forms their bond. In any case, I think it needs to be something deeper than simply acting alpha all the time, and never slipping up and being beta, but there is something to that too. I try to maintain a masculine role, and that requires being emotionally strong and stable.