fairyJo, wow! I love your photo of your crochet, so I'm linking to it! Here it is, hope that's OK.
Right, we're ready to do the rest of it, it gets easier now because you have some structure to work from. First of all, before you start a new row you need to flip the work over so your hook and the current loop is at the top-right of the work, then work across the top of the work to the left.
There's one more stitch in this that you haven't used already; a double crochet. Just put the hook through the allotted hole, put the wool over the hook, come back through the hole then hook the wool again and pull through both the loops on the hook.
Row A: Chain 3, then double crochet into the space in the previous row where you just did a chain instead of going down into your first line of stitches. Chain 3, double into the space .... you get the picture so just do that all the way until the end of the row. Do a double into the top of the very last stitch in the previous row when you get to the end. You end up with a series of loopy bits joined on to the blanket at intervals.
Row B: Chain 3 stitches (these will go upwards and pretend to be a treble stitch), then do two trebles into the nearest of the loopy bits. Now chain once and do three trebles into the next loopy bit from the previous row. Keep chaining once and doing sets of three trebles into the next loopy bit.
That's all, repeat rows A and B alternately until your blanket is the size you wanted! If you're still feeling keen when you get to the end then let me know and I'll post instructions for a simple border - the one on mine was a bit crazy because the blanket came out rather small, I didn't really think about how big a baby is before I started.