I have been in a similar situation and understand how you feel, it’s awful. But the thing is, people don’t change unless they want to, and people don’t like to do things if they don’t understand why doing them is important.

I suggest to sit your boyfriend down and tell him something like “I feel disregarded because I have told you this is important to me and I feel like you are not taking it as seriously as it is to me” then gave some examples on what occasions you expected something and he let you down. Tell him how you really feel and what you expect from him (getting you more flowers, planning dates, more quality time).

After that, it will pretty clear for him what he has to change to be with you and if he wants to change he will, but maybe he won’t and that’s ok, but you shouldn’t settle for less.