I understand your anger and sense of rejection, to say nothing of the money you need. You will not find a lawyer in the land who would take a case like yours unless you pay upfront.
My sister just successfully won a settlement and promotion from the local Sheriff's office after 25 years of discrimination and not being promoted because she is a woman. And that cost her many tens of thousands of dollars in legal fees that she had to pay upfront! Further, she has a law degree and my brother is a lawyer, but not in labor. So, with all those balls in her court, it was still nip and tuck on the outcome for almost a year.
You weren't there long enough to have any track record about anything. Chances are your state and the company you worked for is "employment at will."
They don't have to have a reason, they just don't like you, that's good enough. Employers CAN discriminate! That's how I lost my last job, one I loved. My last supervisor and I never got along and even though I tried soft shoeing, it wasn't good enough. In that case since I was there for five years, I was able to negotiate some pay and health benefits for awhile, and to not contest my unemployment claim.
You can file for unemployment, that is your right. You might be surprised and find out that they won't challenge you. But they can always make you sound incompetent or something. And if you say to the hearing personnel that you were discriminated against because of your diet, without a religious base, they will side with the employer.
I know it hurts, but don't waste any more energy on this. Move on. And next time remember the old adage of "Go along to get along." It's advice I learned rather late in life. When they wanted a first day on the job lunch and you didn't want to participate, you were done right then. It was an insult to not be appreciative about it.