Reverse is the first to go when you have low pressure issues as reverse requires the highest pressure.
This could be caused by low fluid, a plugged filter, a bad pump, blown seal, bad solenoid or the least common a worn out clutch pack.
As for the other issue, that sounds like you have clutches slipping which could again be low fluid, or a plugged filter or worn out clutches. Given the mileage you likely need to rebuild the transmission. You have all the symptoms of it being at the end of its life span.
If it is slipping and not at the end of its life and the slipping is a result of another issue you will burn out the clutches if you continue to drive it.
I would recommend taking it to a transmission shop and have it diagnosed.
Rich
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Sunday, February 9th, 2020 AT 8:04 PM