Hi!

There are a lot of applications and programs that can help you answer this question... one of my favourites is https://mysteemitfriends.online 

If you type in your Steem username and then click on Upvote Stats then you can see all the people that have ever voted for you, and how many times... you can also see who you voted for.

Using the different sections of MySteemitFriends you can also find out how much money you've been voted for, and all the interactions you've had with people.  I love this tool, I find it so handy!