I'm 17 (M) And It seems like I cannot get a deeper voice for some reason. Puberty did me the MOST dirty and BARELY did anything to my voice. And...

Seek a lower vibration. Practice. Humm

• Relax your vocal cords, lower intonation is a more open throated expression. More air, more open. If you take singing classes they teach you that kind of stuff.

• Masculine isn’t necessarily a pitch, although deeper is interpreted as more masculine in context.

• Know where you fit and expand what you’ve got. Try imitating others, and don’t constrict your throat trying to sound deep.

• Try thinking of it like you’re yawning while talking.

• I recommend starting with YouTube and channels like Trans Voice Lessons' older videos.

• Relax your jaw, shoulders and throat muscles. Feel your throat opening up and your larynx descending. It helps to yawn.
  Now spend a few minutes every day - or as often as you like - humming in that state, going as low as is comfortable, then just a bit lower. Don't force it, and don't try to power through any pain, because that'll make your voice tense and high. You can get a tone generating app, and harmonise to a frequency, lowering it carefully.

• You could, however, try to talk better in general. Not pushing for a deeper voice, but for a more relaxed tone. Speaking with more confidence and enunciation. That can actually help you overall in the long run