Am i coocked

Can someone get sciatica from bad posture cause I have had back pain for 3 years and i did mri 2 years ago and it turned out fine and later I discovered that i had an anterior pelvic tilt and weak back muscles which resulted to back pain but recently i started to experience pain in my left buttox area for 1 day with numbness in my 3 middle toes then the pain disappeared now i only got the numbness does that mean i have herniated disc or something else i have been rotting in bed for the past couple months