Your best option in regards to getting assistance with paying for your education, is at educational institution you are presently affliated. If you have a strong science background, perhaps your immigration status will allow you to do some low level science related work. (ex. work in a lab, tutor, grad. assistant, research associate etc.) In regards to PA vs OT, I am only minimally familiar with both. Though, I believe the PA route will give you more career options and you might be able to convince some ER in a smaller US geographic setting to sponsor you. I say this because there is suppose to be a strong need for physicians and those that can fill in for physicians, especially primary care providers.