Me [25m] and my friend [31f] is not sure about my feelings

I'm a 25-year-old man, and my friend is 31. I've had a crush on her since before we even met. Once we got to know each other, we became good friends. Over time, our friendship grew stronger. She opened up to me about her emotional struggles, low self-esteem, and other personal issues, and I was always there for her whenever she needed someone. She has even told me that I helped her overcome many of those problems.

As time passed, we started talking every day for hours. We'd discuss our days, gossip, share personal things, and sometimes even go on late-night drives. Naturally, my feelings for her grew stronger.

Eventually, I decided to shoot my shot and asked her if she'd like to date me. At first, she said no. However, about an hour later, she called me and said, "Can you give me one week? I'll answer your question then."

When that week was over, she told me she didn't want to lose me and wanted to mentally prepare herself for a relationship because of her past experiences. She asked for two months, and I agreed because I genuinely liked her and didn't want to pressure her. She was everything I wanted in a partner.

After those two months passed, I didn't bring it up because she was dealing with work and family problems. I wanted to be understanding. Four or five days later, she told me she needed more time because she hadn't been able to think properly about us due to everything going on in her life. I accepted that too.

Around 20 days later, I became frustrated and asked her if she had actually thought about us because it had already been two months and nearly three weeks. She then asked me, for the last time, to give her one more month, promising she'd give me a final answer. I agreed again.

The problem is that this entire situation has taken a serious toll on my mental health. I have very deep feelings for her, and living in uncertainty for months has been emotionally exhausting. She keeps telling me that she likes me but needs more time to decide if she wants a relationship.

When I confronted her about how this prolonged uncertainty was affecting me, she said she didn't want to lose me. She asked if we could remain friends if her answer ended up being no. I told her honestly that I couldn't do that because I wouldn't be able to watch her date someone else. I said I would rather leave respectfully and let her live her life.

She then told me she wouldn't date anyone else and that we could still be best friends, which honestly doesn't make much sense to me.

As of today, there are still 15 days left before the deadline she asked for. But I'm wondering: if, after taking all this time, she still says no, wouldn't that make me feel like I've been led on? Especially because I've told her multiple times that she doesn't have to say yes just to spare my feelings—we could remain friends if that's truly what she wanted. Yet every time, she's the one who says she wants to give us a try and asks for more time.

At this point, I'm emotionally drained and mentally exhausted. I don't know whether I should confront her one last time now or simply wait the remaining 15 days and accept whatever answer she gives.

tldr my friend is not sure about my feelings and keep delaying answer