How can I sell or give away my jetblue travel credit ?

You cannot sell or otherwise transfer your travel bank credits.  No one else would be able to use them.  You CAN use your credits to purchase a ticket for someone else, which is not something that all airlines allow.

The ones that say I can't , yes I can , even jetblue says I can . They say I can sell them or transfer them ... I think I made a mistake by putting " travel credit " what I meant to put is 

" $61 in my travel bank " 

The fees invoiced in the transfer outweigh the value of the miles.  On purpose . . . All miles rates are now changed at the will of the airline. This makes your miles worth LESS than nothing. And it sounds like you are not gonna earn anymore for YOU to use, even a cash/miles split.

Almost guaranteed that the rules on your travel credit are that you can't sell, trade, transfer or otherwise your travel credits. This is the case in many/most travel credit scenarios. And it sucks.

But maybe try on ebay a different way or may craigslist. Just because it is against the rules doesn't mean it can't be done. Rules are meant to be broken.