There are many women who would be uneasy in this situation. This is a very high profile way to live with many opportunities to meet women - I get that. So don't be too hard on yourself. But you have to either accept that he is a good guy or let go. You can't make him no a musician so you have to find ways to occupy your time, plan out frequent contact and take the ticket. Many things could change about his plan. He could end up not being successful, he could really miss you and want to come home, he could decide this life is not for him. Don't plan out his entire career because he could very well not end up being in this lifestyle for long.
I would accept the ticket and take it one day at a time. This will give you a feel for this life. But if you think you really need to reflect then do so. You have to decide from what you see if you want to embark on this life at all. It is a big decision and many women wouldn't do it. Don't settle for what you don't like. I would reflect to a certain extent before he goes.
If this has been helpful press accept