I feel you! What's been the biggest motivator for me for the past couple of years is David Goggins. His mentality and wisdom has really helped me to push myself and be better than I was yesterday.

I highly recommend his audiobook, Can't Hurt Me, because then you get a deeper look into his past and what made him who he is today, but his compilation videos on YouTube are effective as well.

Best of luck to you; stay hard!