Relationship advice please!

[DropDead-]

Hi there, I've not been on here for so long, but need advice. I've been with my boyfriend for nearly 4 years now and we have the best relationship. Last year we went abroad and did some volunteering. We met lots of lovely people there. A couple of months after we got back I found messages on his phone from a girl who we met volunteering. Lets just say they were talking for a while and their texts were very dirty. Obviously I went mad when I found out, it took a while but I forgave him. We planned to go back to the same volunteering place this year(we go next week). After booking it, I have found out that this girl from last year has returned to the volunteering place and she's staying for a year so obviously she'll be there for my whole time. I am very very scared, not because I don't trust my bf but because I know that I will be upset the whole time. I'm a very paranoid, scared person anyway but I am petrified. My confidence has always been low but now its rock bottom! Sorry for the long message, I would just like some advice on how I should approach this.
Thank you xx

[AllButWanted]

can you talk to your boyfriend before you go about your worries? maybe that would help if its an option.
if not then try and focus on your volunteer work remember who you are there for and be civil with her it can be hard when someone you were friends with has betrayed your trust. but you have to think you have forgiven your boyfriend so maybe try and forgive her she might be feeling just as anxious of seeing you because of what she did.
i hope your okay xx

[Kyaneos]

I agree, I think the best option would be to voice your concerns and worries with your boyfriend, he might be just as worried and doesnt want you to be upset