Product: Student loan

I was laid off from my job along with 40 % of their staff in XX/XX/XXXX. I was 2 months short of turning XXXX. In XX/XX/XXXX I lost my only surviving daughter and I buried myself in work to distract from thinking about her all day and falling into deep XXXX. When that was also taken away from me I had to make some decisions. Firstly, I am a responsible person, but with limited funds, I pay what is essential to live and I could not at the time continue paying Discover Student Loans, a private loan I got in XX/XX/XXXX. I sent them a letter explaining what happened, but not a nice one as they are predatory about the loan in my opinion. 
They used to call & leave 8-10 messages a day, but then they would just call & not leave messages, sent several bills, but I had other bills to deal with that were crucial like rent & car payments, etc. 

In XX/XX/XXXX, I decided to retire early at XXXX starting in XX/XX/XXXX. The jobs that were similar to what I did for the XXXX XXXX XXXX XXXX XXXX XXXX were paying at least $ 20,000/yr less than what I was making. Also, who wants to hire a XXXX-yr-old to work full-time and think that they will be retiring soon or that I am too old to learn something new? More importantly, after losing my girl, I just didn't have it in me anymore to jump through hoops & act as if I'm going to be 100 % living for the company. I was given 2 blows within 6 months at a vulnerable age. 
Discover Student Loans went after my brother who was my co-signer. The loan was so old I did not even remember I had a cosigner. He is retired and on a fixed income but they scared him enough to make him pay {$480.00} to catch me up. I got 1 letter from Discover saying he did this. Then I got another letter saying he has agreed to pay $ XXXX/month in their auto-pay program. I spoke with their head collections officer who just did the robot thing, " I understand, blah, blah '' but you still have to pay us every month. The balance is {$2900.00} now, I've paid for so long. 
I do not want them to take money from my retired brother every month and this " officer '' assured me that the letter I received saying should not have been sent and they will not do this to him. I do not believe them. I did get 57 days forebearance from this person, but after that I have to pay $ XXXX/month. As an early retiree, I will also be on a fixed income and can only work part-time. I asked this officer if they could lower my payments to {$30.00} or {$40.00} per month. He said no. 
Discover has had several problems in the past and have done a little trick with me in past many times. They would send a bill one month, forget to send it the next month. The next thing you know they are now charging me for 2 months and now added a late fee.This practice was easier in the early XX/XX/XXXX, but continued after XX/XX/XXXX. If you are a busy person it is hard to keep track sometimes and I think they " banked '' on this. Also the bills came in many different forms, some with account numbers, some from different offices. I don't know if this is relevant but there it is. 
I am hoping you can help me get an agreement to pay them $ XXXX/month and that way if I have more money on some months I can pay them more. For {$2900.00} and for our situation, ( both of us retirees ) I don't know why they are so monstrously greedy, but then they hold all the cards. They are a big corporation that doesn't pay taxes and can cheat us whenever they want. We don't seem to matter in this day and age.