@Danish Mohammad even after refusals you were able to do all maneuver second time, which means you and your car both are capable. 3.8 SWB has lot more power and better power to weight ratio than my LWB. Definitely change of tyre should boost your confidence and performance, but if you are opting for higher tyre profile make sure its not touching the fenders, if so you have to cut your bumpers.
I am wondering why you have to be too concerned while driving with carnity convoy. We all have both good days and bad days, these all are experiences. If you leave the thought of refusals behind, be relaxed with more concentration and try to push a little more if you see churned up sand or steep incline you will be able to avoid refusals.
See the amazing support from every one and you should not give up easily, I hope to see you tomorrow as usual and focus only on enjoying the drive!!!!