I'm sorry you're in this situation. A lot of these costs come with the territory of accepting to be a bridesmaid.

1. Where are you getting alterations done? $200 is way higher than I've ever paid, even for major alterations. Try to find a local shop instead of relying on DB's.
2. See if you can borrow shoes from a friend, or find some on resale if you need an exact style to match others.
3. Do your own hair and makeup. If you're not good at it, start practicing now or see if any other bridesmaids are able to help you on the day of.
4. As for parties and gifts, you don't have to go to to any bachelorette parties. I know there is pressure to attend, but you can talk to the bride privately and say you're unable to go. Money doesn't even have to be part of that conversation.

As for your friend who owes you money. You need to approach that seperately from wedding planning in general. He's also probably a bit strapped for cash right now but you need to work with him on a solid date where all of the money needs to be paid back by. You can work out a payment plan, if he needs.