I'm assuming he hasn't always been like this, since you say he's not going the extra mile for you "anymore." That tells me he has entered what I call "lazy boyfriend mode." You've been dating a few months, things are going okay and he's not feeling the need to try that hard anymore. It happens. It usually takes longer than three months, but it happens.
Just talk to him. Women get too hung up on sounding needy. You are needy: you need him to get off his butt and do fun things with you. It's a reasonable request; talk to him about it. Tell him what you need. It's called communication, and it's required for a healthy relationship. Do it with tact and love, and you will very likely get what you need.
Thanks for the question.