I've been with my husband for 20 plus years and I have a few observations and a few tips as to what has worked for me.
Previous boyfriends were 'nice' but didn't make me think, annoy me, put up with me criticising them |(without sulking like a 5 yr old) and frankly didn't treat me as an equal, either by not treating me in the same way as others or by expecting less of me than of others. I had realised that they weren't right for me as they bored me very quickly and when I met my husband, I realised that I needed someone who didn't. I hadn't realised this until I met him.
MrShush annoys the crap out of me on a regular basis and has some annoying habits..... and I'm 100% sure that I do the same to him, but neither of us hark on about them and instead try to make a joke of it unless a real issue. He has some personality traits which, given a choice, I would rather he didn't have but with them then comes other traits which might not be there without the first IYSWIM. Both he and I have changed significantly in the 20 years we've been together and I'm sure that we've rubbed off on each other so we're far more similar now than we were when we first married.
We made a decision early in the marriage as to whether we were going to treat both our careers as equally important, whether I would be a SAHM when kids were little, whether we would move to go to better jobs etc. We never took it for granted that we wanted the same things out of our life and had some long discussions over dinners and drinks as to where we wanted to be in 5/10/20 yrs and what we wanted for our kids too.
Both of us try to 'take up the slack' for the other when it's busy, when stressed, when sad, knackered etc and are just thoughtful for the other with little things which might just make a big difference.
I can honestly say that I love my DH far more now than when I married him and I'm delighted with my choice. I also do think that it's a bit of luck sometimes though as I hadn't realised how marvellous a father he'd be when we met and that he had so many other qualities which I didn't know about until life threw us a few curve balls.
Keep trying, keep 'investing' in the relationship and trust your gut.