Why Do I Trust in Allah's Mercy for Everyone but Myself?

Assalamu alaikum, I always remind others about how merciful Allah SWT is, how He forgives all sins, and how no one should lose hope in His kindness. But when it comes to my own mistakes, I find it hard to truly believe I deserve that same forgiveness. I know it in my mind, but my heart keeps telling me I've messed up too much, let Him down, and gone past the limit. Does anyone else struggle with this feeling?