my sd card wont format

I was trying to turn on bit locker on my 64gb memory card. the encryption had not completed and power went off. I pulled out the card and when I tried to complete the process it did not start. now my computer douse not display it in the my computer part, it won’t format. at times I see it in the computer manager but it displays only 30mb. in my phone it asks for a password but the password I had set is too long for the phone space. please someone help