If your boot loader is still in tack you're still in good shape!
To check hold down your power button and do a soft reset, this well
put you in boot loader mode ( to exit boot loader mode just do a normal
Ok now if your boot loader is still in tack trying doing the upgrade
using the SD card boot loader method (for info on this method do a search
on the subject in this forum).
T-Mobile HTC HD2
ROM: JW MIUI Sense like 1.11.18 ML Lite [Tytung r14]
Bootloader: MAGLDR 1.13
Recovery: S.ClockworkMod Recovery v22.214.171.124