Replace the motor for sure but don't go for the cheapest motor you can find. You do get what you pay for.
Your overall systems aren't that old yet. You have plenty of serviceable life left in them. Depending on what you've got, you can get another 10-11 years out of it before you have to start thinking big $$$ on a system upgrade.
For some heat pumps, it "can" be a DIY job because it's a relatively easy swap on some models.
Also, as someone said, you get your heat back right away too.