Replacement PR. Not support of EEA national

Hello everybody!

I would like to explain my situation, I am confused.

I have lived in the UK 5 years and 6 months. Working around 5 years. I got my UK permanent residence card in August 2018.
In October I lost my wallet with my PR card inside.

I applied to the replacement of this card. The application was rejected because I did not attached the ID card or passport of my EEA husband. In the letter what they sent me, say "I cannot appeal and I will have to apply again and provide his passport". I am confused because I had understood the next:
1. Once the non-EEA(Colombian) get the Permanent residence card(after 5 years), I am not more dependent of my husband, for instance, if I divorce this would not affect my status of my permanent residence.
My first question is: Why they ask to attach document of my husband for a replacement of a lost card?
What can I do regarding with this application if they do not allow me to appeal?

2. I have split up with my husband recently and he does not want to support again this application providing his passport.
What things can I do? how can I apply for the replacement card?
I have though in three scenarios:
A) Can I apply by myself and say I am separated from my husband? This will complicate my application? will cost much money?
B) Wait and do not apply for the replacement card and in 6 months when I can apply for the UK citizenship just apply for this one.
C) I was grated the Portuguese citizenship but it will take another three months to have documents to demonstrate this new citizenship. How this could help me? I do not want if I change my circumstances about my nationality, I would have to wait another 5 years to get UK citizenship.

3. I still hold my previous 5 years residence(a sticker in my passport). I have a trip abroad next week.
Could I travel without my PR and show the previous 5 years residence and explain once I arrive to UK that I lost my card and I am in the process to apply a replacement?

Please any advise I am happy to hear,
Thank you very much for any guide of this questions.