Is having a "sugar daddy" immoral?

Because I have one that I’ve only met up with once, and he gives me money every time I’m in a jam. It’s so hard to ask someone for money, but he’s so generous and it’s like him giving me money makes him happy. He thinks I should focus on my studies, and since I have a great (but unpaid) internship at a local clinic, I don’t have time for a regular job. I’m at ends with myself, but I know I will suffer fiscally if I cut him off. At the same time, I want to be independent… but that doesn’t seem possible right now. My school and internship are taking up my life =(