Pro1966
Honestly, the FAA dispatcher license is going to gain you nothing in the UK, if you can already show that you have passed your ATPL gorund studies and hold a CPL. These studies cover the knowledge requirements for EUOPS and exceed the ICAO Doc. 7192 D3 ops/Flt Dispacther training syllabus. Also, in the UK we don't have flight dispatchers as they are known in the States. We have airside 'ramp'dispatch' and Operation Officers, although a few foreign carriers do have 'flight dispatch' offices in the UK.
If you have completed performance studies with your fATPL, why not apply for a job in airline navigation services, write to SITA in Hounslow who have a large flight planning and performance section. You have obviously made an investment in your flying and studies, try to get a job where you can use that to your advantage. Also, not all airlines frown upon aspiring commercial pilot working ops, be honest about your aspirations to fly and keep keep trying.