Hi everyone, this is so long, I'm sorry 
Me and BF together for 4.5 years, lived together for 2.5 years; marriage on the cards soon but not engaged yet as I feel too young. I'm mid-20's and him late-20's, no kids. He likes his job, I hate my job. My job is in a moderate/smaller industry but lots of transferable skills; the industry overall is very interesting but my particular area isn't, so I'm hoping to move into a different area asap.
BF has a 2 year job offer based in a European city close by which he's worked in before (about 1 hr plane ride away). He has asked me to come with him as he knows how unhappy I am in my current situation but I'm really worried that either I won't find a job I enjoy in the new city or I won't find one at all (we don't speak the language but everyone over there is fluent in English, it's western Europe). His salary can support us both indefinitely and we won't struggle. I also worry if I'm unemployed for 1-2 years what will my prospects be for my industry when we return to our home country?
BF has said that he won't go if I don't want him to but I wouldn't do that to him; he's always wanted to live abroad and this is a fantastic opportunity for him so I'm definitely making sure he goes! If I can't go right away then the plan is for me to stay behind in our flat and we see each other at weekends etc. (we did this before for about 6 months when he worked in this same city about 2.5 years ago) and I will join him when I've found something over there.
I'm desperate to pack in the job that I despise and go with him regardless of if I have a job lined up (his job would start in Feb-March 2019). But the sensible side of me thinks it's ridiculous for me to do that when I have no job security there! BF says it's totally up to me and is being very supportive but I can tell he's upset that I may not be able to go right away, he said it won't be the experience he's hoping for. Can you all give me your thoughts on this please? It's starting to upset me quite a lot and I don't know what to do.
Any and all opinions are thoroughly appreciated!