and AM2+ should also work with AM3 correct? If not, I'm in trouble.
If you mean AM2+ mobos with AM3 processors, then yes, that's correct (provided your mobo maker provides the requisite BIOS update). In fact, my current desktop has this configuration -- Asus M3A78-CM motherboard (which is Socket AM2+), and a Phenom II X4 CPU (which is Socket AM3).
If you mean AM2+ mobos taking AM3+ CPUs, or AM3 mobos taking AM2+ CPUs, then no that is *not* supported.