Hi there james8540,
I would say that you have two options.
1st one: Borrow an external drive from somebody, back up the data that is stored on all the partitions except for the Windows one. After that delete all the partitions except for the System one. Then, you can create some new partitions. I would say that this is the safest approach.
2nd one: Try merging the partitions as well as allocate the unallocated one with some third party partition manager software. Keep in mind that some things could go wrong during the process so data back up is advised as well.
Apart from all that, as you had unallocated space, you should have either extended one of your existing partitions or create a new one.
Hope this will help,
D_Know_WD