What Causes A Feeling Of Something Struck In The Throat?

When I wake up in the mornings I have a lump or something that feels stuck in my throat or a pressure. This has been going on for a few years now off and on. Sometimes the lump/pressure stays for a few hours and other times it goes away after a few minutes. It seems to be getting worse. The lump/pressure makes me have the sensation of throwing up. My mouth gets watery but nothing ever happens. I do not smoke and have recently lost 20 pounds so I am no longer extremely overweight. I m 5 5 and weigh 158, female 31 years old. I do not drink either. The sensation from the pressure is so bad sometimes that I can not eat because I m afraid it won t go down or I ll choke. Please help. How can I get relief?