I don’t know what $dorigen is – but you can’t find your </h3>
because of your if/else condition. I don’t see why the else is needed at all. Replace
else { ?> </h3><?php } ?>
with
</h3>
in both places it is used.
That said, if you only want to show the entire post-meta div when the meta values are set, then you should do something like this (untested):
<?php
$firstCF = get_post_meta( $post->ID, 'firstCF', true );
$secondCF = get_post_meta( $post->ID, 'secondCF', true );
if ( $firstCF || $secondCF ) {
?>
<div class="post-meta">
<h3>
<?php if ( $dorigen ) { ?>
My text: <?php echo $firstCF; ?></br></br>
<?php } ?> </h3>
<h3>
<?php if ( $dorigen ) { ?>
Other Text: <?php echo $secondCF; ?></br></br>
<?php } ?> </h3>
</div>
I left the dorigen stuff in even though I don’t know what it’s for.