I don't like all the pressure that gets put on saying it. I think it's more important to feel it and show it. The whole "say it hope they say it back" thing doesn't sit well with me; it feels like a silly game. That said, I do find myself stressing about "will he say it, should I say it?" I try not to this, and just say it when I'm sure I feel it.

My master does not like to talk about his feelings, so I never really expected him to say it first. Maybe Doms don't have a rule about not saying it first, but tend to be stoic about their feelings and so usually don't?

Like you said, he probably knows you love him by your actions and your submission. He probably assumes you know how he feels about you. You sound like you already know this, and it's just stressing you out to not have it said. I felt like that, anyway. I knew it was stupid (like I said I don't like the "who will say it game") but I couldn't keep myself from doubting. So I said it and everything was a million times better. I remember the conversation exactly:

Me: I love you.
Him *This is good nod*
HORRIBLE SILENCE OF ANXIETY DEATH
Me: How do you feel about me?
Him, taken aback,: I love you.

He said it in this tone that was like "Of course, you silly girlie."

So, having taken the plunge myself, I say go for it. The worse that happens is he knows exactly how you feel, which can only be a good thing.