37yr old 198lb 5'10"

Most recent lifts,

Squat 115kg 3x5
Deadlift 130kg 1x5
Bench 83kg 3x5
Press 46kg 3x5
Row 60kg 3x8
Chins (bodyweight) 8,7,6

Been running LP since January (29 workouts thus far). Everything was going great, lifts were moving up steadily with decent form then recently something happened at 115kg on the Squat, the first rep went to shit, very slow decent, grinded it out then picked it up the rest of the set. Unfortunately, i tweaked my low back due to the poor form in the and i just cant get 117.5kg. Its like i have fear or mental block as soon as i unrack 117.5kg of my lock back going when i decend. My press is feeling very heavy now too. Got to 50kg and failed it 3 workouts so deloaded and trying to work back up in 1kg increments. Can switching to 5x3 help here?
I am also stuck as to where i am phase wise. Should i be deadlifting only 1x per week at this stage or more? Ive been alternating deadlift with Rows & chins. I decided just to use Rows instead of Power Clean. Im not sure if i should be at the stage of adding the back extension/chin day along with a light squat day at this stage? I might also add Ive been trying to get through on 2,700cals and try recomp as my bf is around 25-30% at a guess. My weight has maintained around 198lb-200lb with odd fluctuations.

Appreciate and help/feedback as to where i appear to be going wrong or how to overcome Squat fear. A few workouts ago i had my sights on that 315lb Squat but that seems way off now.
My goals for LP was to get
315 squat x 5
405 Deadlift x 5
225 Bench x 5
135 Press
Harsh reality has kicked in of late though and now im unsure.

HELP!