as you don't own all the needed equipment and instrumentals to record drums, bass, and anything else except for guitar, sadly, yes, you will need a MIDI controller so you can easily play what you have in mind for other instruments, in Digital Audio Workstations like Cubase or Reaper. MIDI controllers will use certain sound libraries (for bass sounds, drum sounds) which are either free or premium paid content. It's not hard, it's only harder until you start. I am a guitarist just like you, into music for a long time, been to music college, and still haven't managed to end a proper song because I never really tried. TLDR: Try.