Hey man welcome to the forum. If you want to get more help please start a new thread.
A couple tips till then;
put a multi meter on your subwoofer and see if it still reads 2 ohms at each voice coil or each pair of pos/neg (can be a little different than 2 exactly). Also can you move the cone downward at all? or is it frozen in place? So long as you can move it and hear no rubbing like the coils rubbing you could still have a perfectly good sub.
check your fuses, wires, grounds, and rcas to make sure you haven't gotten any issues with the amp or signal.
Check your filters on your radio and amp. If you feel like you can't get anything below 100Hz to play you might have a High Pass Filter at 100ish Hz stopping all frequencies below that from playing.
Here you can see the differences between a High Pass and Low Pass Filter. High Pass allows for frequencies above a set point to play normally, attenuating those below it. While a Low Pass does the opposite. Attenuates everything to be quieter above a set point while keeping the frequencies below a set point at normal levels.
I went through that whole spotify rabbit hole because I just wanted the files on my phone instead of having to deal with another device, but you can easily put the files you download off D'Amores website onto a USB drive or SD card (whatever your radio has compatibility for) instead of a CD player since you don't have one.
Sub brands you may want to look at for that power rating include, Fi, DC, Sundown... to name only a few. Really my opinion is to find out what you want from this sub then find a sub that can do that, low frequencies monster? great numbers on the meter for competing? or just simply SQL where you have a great frequency response of your subwoofer for more of a sound quality loud.