It's important to note that smiling isn't just smiling, why you're smiling and as a consequence what the smiling says about you is what matters.
I still smile a lot when I'm interacting with people in general, but it comes from a very different place than it used to.
I remember back to the very first date I got when I started working on myself back in 2013. I was very nervous throughout the whole date which lasted around an hour, I was smiling and laughing some, but it came from a place of insecurity. I was not doing it because I enjoyed myself with her in that situation, I did it to constantly relieve the tension I was feeling in the situation. Simply put it was a nervous smile and I would bet my life savings she could absolutely tell how insecure I was based on that alone.
Now I have a confident smile. I naturally smile when I have a good time, it looks different, it looks way more attractive, it's a different expression of a smile altogether. I only laugh if I genuinely find something funny, never nervously to dissipate tension. If anything I can use my smile to ADD tension if the interaction is becoming a bit too flat and boring. I can turn off this smile in an instant if the situation shifts to where I don't like it anymore, this was not the case back when I was nervous because I'd use the smile to dissipate that tension and probably end up smiling more (nervously).
Smiling is fine, don't try to micromanage it. Do ask yourself why you're smiling though and if it's to reduce tension you should work on why you find whatever triggered it uncomfortable.