Question

Hello, honored Rabbi,
Duties of the Heart, Part I, Gate of the Unity of God, Rabbeinu Bahya writes:
"And the clarification of the second premise is as follows: everything that has an end has a beginning. For it has already been clarified that everything that has no beginning has no end, because it is impossible to arrive, with something that has no beginning, at a boundary where a person could stand.
And anything for which an end is found, we know that it had a first before which there was no first, and a beginning that itself had no beginning. And whenever we reach the endpoint of the beginnings that exist in the world, we know that they had a first before which there was no first, and a beginning that has no beginning. For there are no beginnings without a limit to their beginning."
From what Rabbeinu Bahya writes, does it follow that there cannot be something that has a beginning but no end?
If I understand correctly, does Rabbeinu Bahya want to tell us that the world is not eternal?
 
What about the world, the stars, which have a beginning—but how do they have an end?
Thank you very much