Singing is a production in itself. Once I'm psyched up and feel ready, I record several takes - often of the whole song, but sometimes by looping sections depending on the arrangement - and then I Comp in Studio One.
If the Comped vocal is decent, I bounce the Comped vocal to a new track and gently apply Melodyne as needed.
Is that cheating? Well, yeah, I suppose it is, but so what. We apply all kinds of effects to all kinds of sounds in order to present the best quality music we can. The Pros often highlight their 'vocal chains' which are aimed at making the best singers sound even better.
Pitch Correction Plugins? Go for it!