is my diode still usable?

ground and positive pins broke off, bottom covered in solder. cant get solder off

No one is commenting... because you killed it :-/
You'd need to spend hours and have special tools to get that thing fixed...

if you're very careful you can get it working again. You need to connect a wire to the broken positive pin, but keep it isolated from the case.

thanks gooeygus thats what i was thinking. i think i need a desoldering braid

Is it in an Aixiz? if so use a flat file to file the solder off until everything is clean, use a small drill to make a hole where the indents on the outside of the LD flange meets the module. With a very fine solder tip tin the stub of the positive leg.

Get a 10mfd tantalum, shorten the positive leg wrap, a single strand (stripped from a piece of multicore wire) round the leg, solder in place. Solder a red wire to the same leg and a black to the other.

Now solder the neg leg into the drilled hole. Using a pair of tweezers move the single strand until it touches the leg stub that you tinned earlier. a quick dab with the fine soldering iron and you are done........

Ok maybe not quite that easy, it took me about 20 attempts with the blue ray I repaired this way but it worked.

Regards rog8811