Abandoned Disabled Father, Can He Seek Alimony Without Being Married?

Located in TX. My mother and I were his primary caregivers. A little backstory; My parents have been together 25 years and have had 4 kids. My dad supported her and she never worked, until he caught covid, 2 strokes and meningitis which left him bedridden for the rest of his life. He is unable to care for himself at all. My mom and I took care of his needs and always took shifts throughout the day. A couple days ago, she grabbed her things and left without saying a word. She left me with him and I am unable to do it without her. She worked, I took care of him. I worked, she took care of him. I just need a little support as I am a (21F) about to enter college this fall and it’s weighting on my shoulders. They were never married. Can he/I seek alimony? Spousal support? I don’t know what else to do. She left me all alone. I do everything for him. I wish she would have let me know she was leaving is all.