if you use bitcoin core, abandon transaction to stop broadcasting, and re-create tx with higher fee then broadcast it again
if you have problem with broadcasting, get its signed hex rawtx and push it to some nodes
for eg. go to blockexplorer.com and check your old tx, if it doesn't exist or dropped, push your new tx thru this node
pushing your new tx on a node still having your old tx in its mempool will resulted auto reject pushtx