It is very easy to SPOOF or FORGE the FROM: address on emails. It is like the return address on an envelope, you can write anything in that position. Your friends/family just need to be aware of this and delete any suspicious, unexpected messages. They should not even open the messages. They should increase the sensitivity of their spam filters if possible.
Once spammers have a valid address, they will continue to use it. If the forged messages bother you enough, I would recommend that you get a new email address and let all your contacts know to expect communications from the new email address ONLY and ignore messages from your old email.