Hi Oshun!
Just wanted to welcome you formally. I also wanted to let you know that despite the difficulties that you may encounter by not being married or getting married to someone in the UK, you can still harness the power of you dream.
It's hard and not perfect but where there is a will there is a way they say.
I lived illegally and legally in several different countries and can tell you not to let the naysayers get in the way.
I do think you need to be realistic and think about some of the "what if's", but don't let them defeat you.
How many older people that have truly experenced life to its fullest do you see being miserable? It is those that never live any of their dreams that get to an age where they are no longer able to do much about it.
Sorry about the rant, but I am sure that in the future you will hear plenty from more grounded folks than I.
Try school, exchange programs, volunteer networks etc. Good Luck!