Big Comittment

I recently Graduated from uni and have had to move away for a job. Ive been with my boyfriend now for about 6 months but we have been friends for 3 years. Its really hard being away from each other and now he is considering moving over to be with me. I love him to bits and we had previously discussed the topic but decided to wait for a bit to see how things go. I love love him to come over but I'm worried that that is just me being selfish as he would have to leave his entire life behind. Ive started stressing that if it starts to get tough... which i guess can be expected if we are living together for the 1st time he will start to resent me and stop loving me and seeing me in the same way :S then again it could work out really well etc. Im so confused about what to do. when he talks about it at the mo i must sound so unintrested, but really its a big comitment and im worried if we rush into it he will regret it and i will lose him. i havent seen him now in 6 weeks... which is the longest time period i will expect to be away from home. hopefully i will get back to dublin every few weeks after this so maybe when im home more often he might reconsider and wait for awhile but if that isnt the case Im scared of being selfish letting him move over and eventually loseing him. Advice???