I always have the problem that my vocals are either present but then sound harsh and distorted. Or they're pleasant, but then the prominent frequencies are missing and they get lost in the beat.

I also have serious problems controlling the S sounds without ending up with a lisp or excessively strong plosive sounds.

I constantly feel like my mixing sounds unprofessional, even though I've been practicing for five years and am slowly developing an understanding of what I'm trying to do. Despite this, I still fail at the simplest things.

Here is my standard chain for my voice; perhaps someone can comment, I would be very grateful for any tips.

(make hip hop, rap)

main vocal:
Pro Q4 (Surgical EQ)
Pro DS
1176
LA 2A
Pro DS
Pultec EQ
Pro Q 4 (Boost some mids & highs)

main into vocal bus:
tape saturation
OTT

sends:
plate reverb
slap delay
chorus
p-compression