Well I've been in a similar situation with my girlfriend on both sides of the fence.
Basically about 3 years ago I fell into a very deep depression and basically didnt do anything which involved leaving my bed for about a year and a half until I she eventually managed to get me to get a job... now I'm fine and she really pulled me through, but she told me that she kept having to tell herself that she loved me and that the situation wasnt forever.
Similarly this last year she has changed quite considerably from the fun-loving girl I met into a -still fun- but now quite conservative person, now instead of laughing at me when I kid around she tells me I'm not funny, she has stopped taking my feelings into consideration and is more-or-less out for herself.
The thing is, I know why she does this (pressure from her final year of a teaching course - she's in a secondary school every day) and I know that before long she will (hopefully) change back to the girl I love, I've tried to make her feel better about herself (took her to manchester for her birthday and spent �700 on a posh hotel/resteraunt/theatre tickets/shopping trip) so she'd realise that she was loved... it worked! for about two weeks then she fell back again.
I snapped out of it with her help and I'm sure she will with mine... the thing is, regardless of age or the amount of time you've been together, a relationship is a two way street and sometimes its possible for one or both partners to forget this, you need to ask yourself if he is taking your feelings into consideration by doing this, and then take a good long look at yourself and ask if you are taking his into consideration.
If you are stuck in a routine then change it, if you cant then tell him that it wont always be this way and ask him to stay... try to make the times you do spend together more enjoyable.