There are 2 possible reasons as to why you are having problems
1. Your synchros are shot... H23 trannies/synchros are not designed for such high rpms.
2. Your clutch is busted, but not to the point where every spring is broken off... aka the clutch never fully disengages from the flywheel.

The second reason is why you have to put more force on the shift lever to get into gear. You should read up on how a tranny works...

Either way you will need to inspect it thoroughly/ get it fixed for it to work properly.
Also, did you ever think of changing your driving habits?
You seem pretty destructive...