It's so hard to say for sure, but I reckon you're probably right....Practice, practice, practice.
What stage are you at? Do you have a recent or current mix for us to hear?
See the thing is, I doubt replacing the mic is going to yield an earth-shattering difference, but I have two cases with about 40 mics, and there are only two I'd use on my voice.........
I
can get a good sound with more or less any of them, but there are only two that I really feel suit my voice.
Same goes for my pal Pete. Any mic will do if it has to, but there's one that just works for him.
Now for me, that wasn't a waste of money, because I wasn't buying them for my voice. I was building a toolkit.
For you I'd recommend trying what you can, through friends, colleges, shops, local studios, radio stations...Anywhere that will let you in.
If you plan to expand and maybe work with other people in future, then sure, branch out and buy some staples.
SM7b to start with IMO.
If not, you could waste a whole lot of money finding your favourite.
Put your location in your profile dude. Maybe you live near someone on here?