can't get my husband in the mood

my husband and I have been married almost 12 years but been together for 19 years. Up to about two years ago we had a great sex life since then it has gone down to twice a month (if I'm lucky). we have a 5yr and I really want to have another before she gets much older. we are suppose to be ttc but he's like it will happen when it happens. I have tried everything from ligerie to a strip tease to naughty texts messages need ideas and advice please help!!!