Currently Army Reserve and TDY at BOLC. I have orders to check into hotel but I live within 50 miles and was told I would loose BAH?

You are on orders over 30 days, you are entitled to BAH Type I, based on your HOR zip code and number of dependents, TDY has nothing to do with that.

What BOLC do you live within 50 miles of?
If it's more than a 20 min drive, you will want to get that hotel room.
Make sure your DTS auth includes Scheduled Partial Payments (SPP) so your card doesn't go delinquent in month two of school.

At the base your BOLC is at there should be a finance office / cadre that can answer this question for you. Best of luck

You are going to get BAH provided you have on hand all the documentation supporting BAH, such as rental agreements, leases, mortgage payments, or in the event you own your residence outright your Tax Bill.

Basically, you have to prove you pay for housing on the civilian side.

New LT's right out of college going straight into BOLC essentially got screwed out of BAH if for instance they went straight out of the dorm or mom/dad's into BOLC.

Yes........... you'll want to stay in the Hotel. No other housing is going to be closer to the school house than the on post hotel. You will cherish every second of time you have in BOLC.

Looks like you are ROTC, so you'll probably experience what Army training is really like for the first time. West Point, OCS, prior service all went through some "fun" when they entered the Army. It's been my observation ROTC officers first get to really see what it's all about in BOLC.