Congratulations! It's very important to take note of every positive interaction by writing it down (maybe a list somewhere?) and you can look it up on bad days to cheer up. It's really just a matter of being happy in general and the more fluent experiences you have, the easier it is to improve (a bit like how our bodies process fat, I think). Though I have to admit I kind of looked down on the advice your professor told you for a second... In the past I probably would've refused to acknowledge that anxiety or nervousness is similar to stuttering, but right now I can honestly say it's pretty much the same thing haha. Cheers!