Could it be a stutter?

Could it be a stutter? I don't have a typical stutter, but I am sometimes incapable of saying things even though I know what I want to say. I don't really block, it's more like hesitation. I get around it by chucking in some filler words like 'like' or 'yeah'. It isn't severe enough to cause me any major communication issues, but it happens often enough for my friends to start tallying the amount of times I say 'y'know'. When I don't use the filler words, I get incredibly anxious about my speech, and I often quickly look for substitutes for words that I think might cause me to seize up or, very rarely, stammer. Is this still a stutter, or could it be something else?