I wonder if we've scared the OP off by now????
Fundamentally 95 min, T5 > T5, connected booking is usually OK, lots of people travelling for whatever reason connect on those sorts of timings every day .
There is (or certainly was) a department at T5 which specifically looked at tight connections and flight progress. If a connection looked like it might fail they would either try to expedite getting passengers through the Terminal, or if a connection had failed they'd proactively rebook for later flights, even before the passenger had landed on the inbound flight. They'd sometimes even send messages to the crews of the inbound flights to pass on to passengers involved, to provide reassurance/info.
Despite the above if the OP is still considering travelling on an earlier domestic flight I reckon things still to consider:
Relative timings of both any available domestic (is there actually an earlier option?) and long haul sectors (is there a later flight same day)...
Is there any knock on to arriving in JFK or EWR late?
Is there any cost implication to changing the domestic sector?
Does the OP fancy x hours experiencing the joys of T5..🤐 or would they rather minimise the experience?
Whatever they decide, hope it works out OK for the OP.