My gf F24 loves me M24 more than she loves herself but just isnt "passionate" anymore

Me M24 and my gf F24(pansexual) have been together for over 3 years now. We got together as students and i am her first bf. When we met she was still a virgin and i was her first. In the beginning of our relationship we were both just as passionate about eachother. We wanted to be with eachother all the time and she wanted to cuddle all the time to kiss all the time and to have sex pretty mutch everytime we saw eachother.

Having both started working we both are allot more tired by the end of the day and shes slowly but surely grown less and less passionate. It started by being tired more often and not wanting to have sex anymore during the weekday. Then it kinda grew thru to also when we are on holiday and she blaims me for wanting to have sex too mutch. During sex its always been mostly me who has been the top and the one who initiates everything but now when we do it feels more like she just doesnt wanna bother doing anything or putting on lingerie or sommething bcs shes lazy. Ive mostly blaimed myself up until now and just told myself i had to do better at taking care of her in that way. Ive been putting crazy effort into it and its only been getting more and more that she says no. Ive talked abt it with her over the past year allot that i wanna find whats wrong and work towards both being happy but she says its her and that she feels to tired bcs of work and bcs she herself doesn't feel attractive (i think she is incredibly attractive😅).

Now more and more im noticing that when i kiss her she just kisses back quickly instead of enjoying the kiss and she snuggles up less when we are watching tv. I feel more like a bestfriend who kisses her when i comme in the door than i feel like her lover sommetimes. Ive talked abit it often with her and i am certain she fully loves me, but shes just not passionate abt me anymore. She doesnt make me feel like im sommebody she wants to kiss or have sex with anymore. Yeah sommetimes (abt once a month and a half) she actually wants to have sex and then everything is rly good but in-between she gets rly passionless:/.

Idk if its my fault or if im just a person with a different love language and sex drive but it just feels like sommething is fading away way too quickly. Like we have the passion of a couple thats been together for 30 years instead of 3. What do u guys think is going on? And most importantly how do u guys think we can balance it out again between us?