Since it's a 6/8, try to convey the feel of a duplet rhythm.
To count a 6/8 is 1 + + 2 + +. Start slow with the metronome with 1 beat equivalent to 1 quaver note; to get the correct rhythm.
To count the rhythm of your piece is to replace '+' with e.g. banana or any 3-syllables words.
New counting will be: [1] ba-na-na ba-na-na [2] ba-na-na ba-na-na...etc.