Hello. Thank you for coming to JustAnswer with your question, and welcome.
Your description of your swallowing difficulty sounds like you have a problem with the esophagus. There are many problems that can cause "esophageal dysphagia", or the problem of food getting hung up in the esophagus. This problem needs to be assessed by your doctor so that it can be treated. The usual problems are strictures or narrowing of the esophagus; spasms of the muscles in the esophagus; or the sphincter that opens into the stomach is not opening and allowing food to pass as it should. It doesn't usually have anything to do with weight gain by itself.
Until you see your doctor, soft foods and very moist foods (added sauces, gravy, etc) can be easier to get down, but you should continue to chew very thoroughly. Also, as you have said, eating very small well chewed bites and following this with sips of liquid.
Here is a link to some reliable information about Difficulty Swallowing.