Will I keep growing and developing? I'm eighteen, I have one tubular breast and I am incredibly unsymmetrical

Asymmetry in size and shape is very common at your age, when the breasts are developing. Usually, a level of maturity in breast development is reached at 19 to 21 years old. At that time, your breasts may be more symmetrical.

It sounds like you are still growing. I advise my patients to wait at least two years after they are done growing in either height, weight, or bra size before considering any breast enhancement surgery. Being patient might eliminate the need for a second surgery if your breasts change from further growth. To see before and after pictures of women with asymmetry and their surgical results, click on the link below. For more information on this and similar topics, I recommend a plastic surgery Q&A book like "The Scoop On Breasts: A Plastic Surgeon Busts the Myths."

Hello and thank you for your question. This is very common.  You are not alone.  There are many options that could possibly help you.   The
most important aspect is to find a surgeon you are comfortable with. I
recommend that you seek consultation with a qualified board-certified plastic
surgeon who can evaluate you in person.
Best wishes and good luck.
Richard G. Reish, M.D.
Harvard-trained plastic surgeon

It is very un probable that your breast even out if they are already that different. Breast size asymmetry is usually fixed during a surgical procedure. Once you don't see any size changes during 6 months , you have probably reached your final size, and are able to book a procedure to make them even.Best wishes 

Thank you for your question. It is possible that you will have continued breast growth in the larger breast over the next year based on your comments stating that there has been a change in cup size in the recent past.  I suggest waiting a little longer before having surgery to correct your breast asymmetry. This will help to ensure a longer-lasting result after one surgery. I suggest meeting with a board-certified plastic surgeon who has experience with these types of surgeries to help evaluate you at this time and then in the future. 

 I'm sorry to hear about your concerns but online consultants will not be help you with specific predictions; obviously, this may be one of those situations where only time will tell.  Having said that, given that you are still growing,  even if it is at a slower pace,  I would give yourself at least one or two more years before contemplating breast surgery. Best wishes.

By 18 years old, it is likely that you will not grow evenly if you have not done so so far. Best to be evaluated in person.