Hi Sylvia,
As far as I've been able to find, Veracrypt is probably your best option. Although you can still download the latest working version of truecrypt, it's development was stopped a ways back and a few others apparently have picked up the code and continued on with it. If you're familiar with using TC's interface, then Veracrypt is going to be pretty much exactly the same.
https://veracrypt.codeplex.com/

A little while ago on list, I'd asked a similar question and also had some wonderful suggestions for other ones to try. I can dig up those emails and post them here if you'd like to read them too.
Take care.