Yes, it's so great to see someone else from the states who wants to study in the UK! I felt like I was the only one for a while there :/
I feel like a lot of people who aren't from states such as ours think it's paradise, and I guess it is when you're visiting and you can enjoy the weather and sights in an appropriate way. But when you have to work outside in 90 degree weather, it's not so fun! And don't get me started on the tourist traps!
Actually, I did a mix of both. I was dual enrolled at my high school and community college for my sophomore and junior year. I earned about 30 college credits this way, then finished the rest of my two-year (Associate's Degree) after I graduated from high school. I studied part time, so it actually ended up taking much longer than I had expected it to. I finally finished my Associate's Degree in the Spring of 2016, but continued to take math courses after I finished because I realized that I wanted to major in Mathematics. So, while I took some prerequisite classes over the summer, I researched universities I could go to in my area with a strong mathematics program. Unfortunately, the only one I could find was way out of my price range. As you probably know, out-of-state was even more expensive, so that was also not an option. I'm currently in a relationship with a guy who lives in the UK, so after discussing it with him, I decided to look into applying to uni over there. I finished my application in November of 2016. I got accepted to 4/5 schools I applied to (Southampton, Queen Mary, Kent, and Newcastle- I was denied from Sheffield as they felt I didn't have enough Calculus experience).
The only thing I can't stress enough if you plan to take the community college route is to take as many classes in the field you plan to study as possible! I had taken courses in psychology, computer science, and mathematics, because I wasn't 100% sure as to which route I wanted to take when I started. Though this wasn't as big of a problem as it could have been for me (comp sci and psychology both have math components), I still got denied from Sheffield and received (what I consider to be) a bad offer from Newcastle because of my lack of in-depth math experience. I managed to offset this a bit by taking Calculus I and Discrete Computational Analysis (both math based courses) this semester, and it helped me to get offers from Kent and Queen Mary (Southampton originally gave me a conditional for a 3.2 GPA for my Associate's Degree, but changed it to an unconditional after I submitted my transcripts).
My advice to you regarding the predicted grades would be to contact the uni's ASAP and advise them of your situation. Most of the time, they are willing to work with you. I had to ask Newcastle to push back the deadline for the receipt of my transcripts as they are taking way longer than expected to arrive. They were willing to give me until the summer, even though the original deadline was three weeks after receipt of my offer. Contact whoever you can regarding the situation, so they are at least aware of the reason behind the delay. I would also try to talk to someone at your school and see if another counselor would be able to step in and submit the predicted grades for you instead.
Are you working with an Across the Pond advisor for your application? If so, I would reach out to them as well and see if they could help you explain the situation to the uni's. If not, I would recommend you check them out! Even though you've already submitted your application, I'm sure they would be more than happy to help answer all your questions, help you communicate with the universities, and help with the visa application if you get an offer you want to accept! Here's a link to the website if you're not working with them already:
http://www.studyacrossthepond.com/