My BF [23/M] and I [22/F] have been contemplating a break so he can "explore" himself and I'm not 100% with it, what do I do?

Ok so my BF [23/m] and I [22/f] have been together for almost 4 years now. We have a very amazing relationship and friendship; we've explored lots of places, made many memories, and truly just enjoy each others presence 99% of the time, but lately BF has been very distant. Aside from family issues going on for BF, he just doesn't seem like he wants to be with me or around me. A few weeks ago BF had gone to the beach and met this guy [G] there. They had a casual and wonderful conversation and the next few times BF went to the beach G had been there as well and of course had more conversations. After the third or fourth time of "catching" each other at the beach, G finally asked BF out on a date. BF, although flattered and thankful, he respectfully declined and stated that he was in a committed relationship.

Speed up to now and BF and I have a long conversation about him being distant and BF tells me he isn't really sure why. We talk and I over suggestions, one of the biggest ones being that he may be bisexual or that he wants to explore that part of him. BF tells me that it is a possibility seeing as he had tried it once before we got together [first time knowing that!]. I want to be open with him and would do anything to make him happy so I suggested a break so that he could explore that. After suggesting it and really thinking about what that entails, I realize I am not super comfortable with BF had any kind of relations with another man or woman because he could fall in love with someone else.

BF expresses multiple times that he loves me dearly and the last thing on Earth he ever wants to do is lose my friendship. Bf also tells me that he just doesn't feel like he can commit to me the way he thinks I deserve, that he is possibly getting cold feet. I'm not sure I can be peachy keen going on road trips and working with him like we already do if he is having relations or dating another person.

What do I do or say to BF?!