Hi holaandlou!
Along with Ms. x0Kiss0fDeath. I also wonder if it is at all possible to stay long enough in the UK to get your UK Citizenship before you leave the UK.
I lived in England for over eight years with ILR but no UK citizenship and I left the country abruptly with the intention of returning within two years. I've now been in the US for over 14 years but my UK husband is desperate to return to England. It's far more complicated and expensive than it was in 1995 and if I could do my life over again, I would have moved heaven and earth to get my UK citizenship.
Back in 2004, I returned to Texas with my children and my husband. I went to the US Citizenship and Immigration Center Field Office and told them that I wanted to make an application for my UK spouse to settle with me in the US. I filed an application for a spousal visa and it's accompanying "affidavit of support" within the US. We filled out the forms, paid our fees and within five months, we received a letter for his fingerprints, FBI checks and a meeting with an officer at the field office. My husband received his "green card" within six months.
My cousin, in that same Texas town, married her Welsh fiance two months ago and has attempted to apply for his "green card" from the US whilst living in the US. It's apparently been very difficult for them because the field office has a very large back log and they are looking at a minimum of six months before they even look at their application. I've heard from other people in my hometown that their applications are taking nine months to a year to be processed from the US. They have been informed that it makes more sense to apply from the US embassy in the UK. Only you, holandlou and MES, can decide whether it is more advantageous to apply from the UK or the US.
Here is a link from the US Embassy in London regarding the process:
https://uk.usembassy.gov/visas/family-immigration/Good luck!