I Have Lump In Neck. Do I Have Hypothyroidism ?

I visited my GP today as i have been having discomfort at the front of my throat - it feels like there is a marble or lump in in (like if you re really upset and have been crying a lot). THis started last Thursday, went away over the weekend (appearing briefly on saturday night) and is back again today. I feel like im being choked. My GP felt my neck and examined me and said that there was a swelling in my neck and it is possibly hypothyroidism or cysts/ goitre on the thyroid - she has sent away blood tests to be done to check my thyroid function and is referring me onwards to get an ultrasound of my neck. I have come into work and the tight feeling in my neck has got much worse throughout the day. I am now getting some throat pain, nausea and im finding it difficult to concentrate. My question is, are these symptoms indicative of hypothyroidism or is it more likely cysts? I am very concerned about this as i am due to go abroad in 2 weeks and the feeling is becoming unbearable. Any advice is welcome. Thanks Details - 25 year old Female - no family history of thyroid problems