It sounds more to me like your Ijust isn't vaporizing the liquid correctly. I suppose overfilling could cause that, but if you aren't getting good vapor, it's possible your device (battery) needs to be charged, or the connection is not good between the mod and the tank, it could be all sorts of things, up to and including an electrical fault.
If you can, perhaps watch a review or two of your device, to make sure you are operating it properly. Removing some eliquid is fine and it will let you know if overfilling is or is not the problem.
Did you feel like it worked well on days 1 and 2? The good news is, if this is the mod and not user error, you should be within the warranty period.
I'm not saying warranty it, I'm saying do what you can to isolate the problem (even go to a brick and mortar if you have one near you, and you get no "vape satisfaction") but even worst case, if something has happened to the setup you can warranty it.
But, more information will allow us to give more specific help and etc.
Best of luck,
Anna