Are these normal feelings I am experiencing?

I was with someone for 8 mos. We had plans to marry, etc.. He then broke up with me. It totally blindsided me n left me devastated. The 5 mos we were apart, he was terribly kind n considerate of me..we never really lost 100% contact (email). Then he changed his mind n we got bk together. I took it very slow and he understood this. Now it is 4 mos since we are bk together but I can't seem to Truly trust/believe in him. I know he loves me but I have doubts of how strong his love is..can he put up with hard times, etc.. Obviously he broke up with me once, it could happen again. Are these normal fears? He is offering me everything and taking the actions to prove he means it but I still feel myself holding bk just a tad..like I am afraid to gv myself fully for fear of bn hurt again. Just a few days ago I was thinking of my hard time during the break-up and I started crying again! What;s your take on this, please!?