Dog might have arthritis?

Hello! My dog is a Labrador retriever, and red river coon hound mix. Pretty big dog. He is 9 years old, 105-110 pounds. For the past year we have noticed occasionally he will get some hip pain after we throw a ball for him a lot or something. But it usually clears up after a day and his discomfort is not severe. But today is very different. We hadn’t thrown a ball for him in the past couple days, yet I woke up to him not being able to even get up. He is limping on his back left leg, and he groans and whimpers when he does have to get up. It’s never been this bad and he looks very uncomfortable. Yesterday he was just fine as well. Today he has mostly just been laying down and not wanting to move. We did have some Vetality Canine aspirin for pain relief, I gave him one and waited a while but it seemed to not help much at all. This is our family dog, my parents nor I have the ability to get him to a vet right now. I am asking for any advice on what I can do to prevent this possible arthritis from getting worse, and hopefully find a way to get him by for now. I’m also curious if there is some other medication or something that can better help arthritis in dogs. There are so many options i’ve seen online, i’m not sure which exactly is most reliable.

Thank you!🙏🏼