Anal...

Ugh okay so I have a younger bf and he's totally into watching porn and gets the idea that anal is something interesting. I've had 2 encounters in my past relationships where the tip slipped in and I cried out in agony and tensed up my body! It felt like my b hole riped. So now I have a traumatizing notation everytime he gets near it. He's been unsuccessful and I've even tried doing it myself with a butt plug I bought from Spencer's as a gift to myself.  And I'm still to scared.. The idea of it hurting frightens me and I won't play with it. Any idea on how to loosen myself up or another toy I may try to make it easier to start the process.. ??  Tips tips tips (literally) lol