Confused about same sex visa process

[stitch626]

So my situation is the following

I am a US Citizen and about 8 years ago started dating my same sex partner who is Uk citizen. Unfortunately he fell into some legal trouble and while he said he had dual citenzhip to stay here in the Us, it turns out he does not and is in the process of being deported back to the Uk.

I want to remain with him and have been trying to make heads and tails of which visa to apply for and I find that I am just getting more and more confused.

By the time he would be settled in the UK and be able to show proof of income to sponsor me we will more likely than not be apart for more than 6 months so I'm thinking I can't apply as "UNMARRIED OR SAME-SEX PARTNER OF A BRITISH CITIZEN OR SETTLED PERSON" How much time can we have apart to qualify for that?

The other option I was looking into was applying for the visa to get married/civil partnership in the UK then applying for the visa to remain in the country. However what has caught me off guard is it appears the fees are the same amount for both the visa to fe married then the visa to remain I the country as a partner of a uk citizen?? So I'm looking at nearly $2600usd in application fees, which would dig into my savings. I would be applying immediately after th ceremony as I want to be able to start working ASAP in the UK and also likely go to school again.

Can anyone provide me some advice about the best course of action to take?? I would greatly appreciate any help possible.