Yes, In Love, that feeling can be reignited.
A Change Can Reignite that Feeling
Doing different, new things together, as you suggested and have just started acting on, is a good idea, as is maintaining wide open communication channels, something it also sounds like you're doing.
We All Go Through Cycles
We all go through cycles in relationships, and sometimes the feelings manifest themselves in a sense of "boredom" or being in a rut. While not everyone can be expected to come up with brilliant ideas on a daily basis to relieve such boredom, it's a good idea to talk about and act on the things that you felt and did when you first fell in love.
Conflict Keeps It Interesting
You said you don't fight, and that, to me, is a bit of a red flag (a pink flag?). People in healthy relationships DO fight. Not constantly, and not about every little thing, but arguments rise, philosophies clash, people fight. And then people make up. That's one of the things that keep relationships interesting. I'm not suggesting you actively search for things to fight over, but you might still be in the "honeymoon" stage and not be seeing or paying attention to certain faults that each other has.
He Acts Like He Wants It To Work
Your boyfriend's emotional expressiveness when you two DID talk about this issue leads me to think that he does want your relationship to work. This, of course, assumes that he's generally sincere and doesn't cry on command.
Four Months Is Not a Long Time
Let's keep in mind, however, that it is ONLY four months. In the larger scheme of things, that's not a very long time. You should both be really sure when and if you declare your love for each other... in the meantime, make sure you have a good time together.