The way it's done per IRS requirements is screwy. They don't make it simple. (on purpose I think.) I suggest you work back through and double-check your selections and entries. If all looks okay, then leave well enough alone. The thing to keep in mind is that with each mortgage payment you make, more of each payment goes to principle, and less of each payment goes to the interest.
The split you're dealing with between the time it was your residence and the time it was a rental is something you deal with only in the first year the property is converted to rental. After that, this split won't occur again unless and until the tax year you change it back to personal use.
It is perfectly possible also, that in that first year the interest allocated to the SCH A plus the interest you pay on your new primary residence will exceed the $750K threshold. But for that to happen depends on several factors such as when you closed on the purchase of the new home. Closing late in the year generally means you paid less interest, and that alone could keep you under the $750K threshold.
