I am 22years old almost 23. . . . My dream life seems to be passing me by.
You must have had some pretty high-maintenance dreams, then! At that age, your life is still pretty much completely open and you can go any direction you want with it pretty easily, I think. Olympic class gymnastics is probably out (but at 5'11", that wouldn't be much of an option anyway). Child camel jockeying is also a lost opportunity. But if you have fairly normal dreams, they're probably all still attainable.
I am . . . 5ft 11 and currently approaching 18stone.
That's not really a bad weight in itself for your height. It depends on how you carry it.
I am starting to give up on the prospect of ever . . . finding a boyfriend/future husband and therefore one day having children.
If that's how you feel, then I have to tell you: if it weren't your weight, it would be something else making you feel like giving up hope. The despair is coming from something other than your weight. Whatever that problem is, that's your real problem. Everything I'm about to say concerning weight is really kind of irrelevant.
But okay.
When it comes to attractiveness and body shape, a woman's weight is actually of very little importance. What is important is the hip-to-waist ratio. According to the studies I've read, a woman whose hips are at least 15% bigger around than her waist has a figure that is consistently physically attractive to men. So if you tend to carry your weight more on your hips than you waist (as most women do), then it's actually making you more attractive. Only if your weight is impairing your hip-to-waist ratio should you worry about it in terms of physical attractiveness.
But the most important thing you can do to be attractive is to be attracted. When you are attracted to a man, you give of a host of physical signs of interest. Men pick up on that. Most men are not looking for a woman they have to win over. They're looking for a woman who doesn't represent a great risk of rejection (of course, remember that delay isn't the same as rejection there's no need to get anywhere close to violating the Law of Chastity for a man to feel like you won't reject him). If you show signs of being attracted to lots of men, men will respond very favorably to you because you don't seem like someone who is likely to reject them.
The best way to seem attracted to lots of men is to actually be attracted to lots of men. Cultivate a strong appreciation for men in general. Nourish that appreciation and let it that light shine. It shouldn't be too hard. We are, after all, created in the image of God.
Until you get there, remember that a good, friendly smile goes miles. Studies have shown that men consistently confuse a smile of friendship from a woman as a sign of sexual interest. If you always give lots of friendly smiles to men, they are almost certain to think that you are interested in them and they will be inclined to reciprocate what they see as your sexual interest. Good, chaste men will, of course, seek the fulfillment of that interest only within the bonds of marriage but they will definitely seek it!
If you feel determined to lose weight for whatever reason, let me add three tips to those I've read so far.
First, drink plenty of water.
Second, get plenty of exercise. Make sure the exercise is something you enjoy doing, or you won't keep at it. I've found that exercise is more important than diet control.
Third, don't use food for any purpose other than nutrition. It is not an acceptable form of therapy. It's not a good drug. It's not a recreational tool. It's just there to nourish you.
Incidentally, I find I eat a lot less when I chew gum a lot.
Whatever you do, I wish you well! Women your size should be doing more breeding!