I’m already quite good at electric guitar, and have developed a good singing voice, however I find it difficult to sing and play guitar at the same time. Serious answers only please.
make sure you can play the song you want really well, like practically in your sleep, then start humming the song while you sing and slow down if you have to, then slowly add in the lyrics, again you might have to slow down your playing while you first attempt it because it is a little difficult at first but the more you practice the easy/better you will become, just like playing the guitar.