Been in same situation plenty of times..
Space the messages out, DONT send 5-6 messages a day. Instead let her know what it feels like to MISS you..
Maybe reply to her message once a week, twice a week max. But when replying, make her want you more. Even things like once every week or 10 days post something on her facebook wall... Maybe a link to something cool - and just basically write 'I seen this and thought you would like it!!!

'
DONT send her 5-6 messages a day and also DONT end conversation with her - as she will just flake big time.
Good luck