I'm just confused. He tells me all these wonderful things and includes me in his future plans and it makes me so happy, but I guess I'm still living with this fear of losing him again. Something just feels missing and I don't know what it is. 
ahhh, now i got you

you dont have to set yourself under pressure...... and maybe its just the weather or the snow, or just a blue week.... just relax.... do not overthing too much. is he pressuring you?
if, then you could say- i need some time--- i love you but i still need some time.
he will wait of course, cause he loves you.

i know this feeling of being scared to lose someone very well...... try to forgive him and try to forgive yourself as well.
for affirmations you can say to yourself, it helps me alot- its for healing yourself---
i am sorry, please forgive me, i love you and i thank you
your fear should be released after doing that.
and maybe pstec, if you dont know it already.
you can search for it in this forum... pstec.... its free and amazing!!!
to get rid of fears, old beliefs, etc....
;)sending you healing thoughts