Sell it and get a .308 or something reasonable to start out with. If you are already worried about recoil, then you are going to flinch, and that's not an easy thing to cure.
This isn't bad advice.
I'll go way out there with something completely different.
Get involved shooting trap, skeet, or clays.
Shoot at least once a week. 100 rounds per trip.
Use a 12 gauge, and not powder puff loads, not a semi.
1oz 1, 1/8oz.
Those rounds out of an appropriate gun are not unpleasant, but they bump.
100 bumps per outing will make your shoulder tender, a week will let it heal.
Doing it every week will toughen your shoulder.
No idea how it works, but it sure did for me.
First time out i quit before 100. Was getting sore and I didn't want to get flinch.
Soon 100 was no issue.
When I got my light(not as light as yours) 300 Win out, it suddenly didn't
seem to kick much at all.
The hardest kicking gun you own, is the hardest kicking gun you own.
The hardest kicking gun you've ever shot.....
Zeroing an 870 turkey gun put that 300 in perspective with 2 rounds.