Hello and welcome to the forum.
Well done on your weightloss to date you have done a fantastic job.
Plateaus mean your body has gotten used to what you are doing and is no longer responding so you need to change something to shake the body up. Keep it guessing to keep it responding. As Kate suggest change something in your diet or exercise routine. So you can see what is working or not maybe try to only change one thing at a time. Also change in your diet does not necessarily mean eating less, sometimes having low cal days offset with a higher cal day can give your a kick start.
All the best and let us know how you go.