I have a 30+ year old house.
I want to add a GFCI near the kitchen sink

This is what I have to work with
From the breaker box

Red - hot breaker 1
Black - hot breaker 2
White - neutral

Both breakers share the same neutral - they are chained together through
4 outlets

Red Outlet 1 (needs GFCI)
Red Outlet 2 (needs GFCI)
Black Outlet 3 (needs nothing)
Black Outlet 4 (needs nothing)

I tried to install the GFCI in outlet 1, but since it just constantly trips.
When I isolated the white from breaker 2 and was just using breaker 1,
it was ok.

Any suggestions??