Welcome to the forum Pickett although I'm sorry about what's happened.
If other members have had similar experiences I'm sure they will be along to when they can to offer their support and advice but in the meantime it may be best to get in touch with the heritage site to see how/where they got this date from and if it can be corrected.
I hope you're able to get this sorted soon Pickett.
Are you sure it's your dad's death record on Heritage that you have looked at? Could it be someone with the same name & place of death but who died on a different month - it happens quite a lot with names that aren't uncommon. The only way to know if the date on your dad's headstone is correct is to go on the GRO (General Records Office) website and order the death certificate if you don't already have it.
