Your other thread on this topic has some excellent advice.
I don’t think the choices are to answer all the questions completely or be brief. You can do both. Provide the necessary details and dates, but get to the point. Have you started composing the letter yet? Try writing a draft and see how it goes. If you post a draft (after editing out identifying details) we can offer editing suggestions.
What’s your backup plan? Are there schools you can commute to from home?