He's complimented me in the past on my 'low maintenance' That is absolutely not a compliment. He’s telling you that he’s glad that you’re so accommodating and that you let him get away with treating you without any care or thought or consideration and don’t try to make him feel guilty about it.
I constantly get 'what's for dinner tonight?' Reply ‘I don’t know, what do you want to cook?’
Or 'what are our plans for the weekend?' ‘I don’t know. I’ll let you surprise me’ or ‘Well you didn’t arrange anything so I’ve made plans of my own’.
Or 'what are we doing tonight' ‘I don’t know, where are you taking me?’
Or if I suggest he arranges something I usually get 'I'll let you choose' ‘No thanks. You know what I like. You can organise it’
Recently it was our anniversary and he completely forgot, I handed him his card and gift and he looked all sheepish and then said 'it's only a day isn't it? We don't need a day to show how much we love each other ‘No DH, it’s not just a day to me. But please, enlighten me. How do you show you love me?’
I often get up and bring him a cuppa in bed on a weekend, I asked him if he'd make me one last weekend for a change and he did - after he'd sighed and rolled his eyes. If you make him one more cup of tea in bed before he changes his ways then I want your address so that I can come to your house and confiscate your kettle!
I do feel like his mother rather than a partner sometimes  That’s because he’s treating you like his mother. It’s his house too and he’s responsible for 50% of keeping it clean and tidy. Personally, I’d give him 24 hours notice that I was not prepared to live like this anymore. If socks get left on the floor, they go in the bin. If he wants sex, tell him that you are so sick of being treated like his mother that you are starting to see him as someone that needs to be taken care of. Nobody wants to have sex with a man child.
There’s lots of stuff written about love languages, but how exactly is he showing his love for you? How does he show you that he values you as a person? That you’re worth spending time & effort on, like you do for him? He started off by taking you out and planning nice things for you, so he knows that it’s a nice thing to do. What made him think that it was ok to stop making the effort?