The SM-58 is a more-than-capable microphone which has been used on countless studio recordings. The key issues preventing you from getting a lively sound are probably as follows:
You are using a USB audio interface - these range GREATLY in quality. Most A/D converters in them are relatively poor from an audiophile standpoint. If you get a higher end one with good reviews (do your research) you should get much better results (it also makes multitracking easier if you get a device with low latency - look for a newer usb 3.0 implementation or even go back to Firewire... I did and it's the best decision I could have made at the time). It seems like this would be a minor issue, but it honestly makes all the difference in the world.
You may be recording too close to the mic. As the SM-58 documentation so prominently indicates, the 'proximity effect' occurring from being within about 6-10 inches away from the mic will start increasing bass frequencies immensely, vastly altering the timbre. Usually you want to be 1-2 feet away, and use your preamp gain to boost the signal to an acceptable level.
Finally, find a good compressor and learn how to use it. In software there are several free options, one from fxpansion called DCAM which I recommend if you can find where to get a copy (I think you just have to sign up at their website). Another good one (Evaluation version only without paying) is Bombardier Bus Compressor.
EDIT: One more thing I forgot helps a ton, especially when you add the vocals to a mix, but it is the most expensive and difficult part of the whole process. Getting a low pass and ideally also a high pass or even bandpass filter (or two, or three...) and using them to tweak the frequency response can give you any sound you want. EDIT 2: Especially if you dynamically modulate the control paramters, i.e. with a triggered envelope.