I am 21 and have no idea where to go with my life.

What's your hurry? You aren't even out of school yet. So many people NEVER figure out what they want to do/be, and many don't get it before they're in their 40's.
If you really do want to find a lifestyle that suits you, start saving now and finish school (so you'll have a fall back, if all else fails). After you graduate, pack a bag and set off on an adventure. Sail to the Caribbean or Europe, work a summer in Skagway, Alaska, volunteer to be a worker on a archeological dig, be a cook's assistant at a logging camp. Or anything else you can think of that might be fun or interesting. There are only the limits you impose upon yourself.

Regarding school:
I have a friend that got a degree in a very highly technical field, worked in that field, and made a lot of money in that field, only to leave it behind to continue studying to become and eventually becoming a working actor.

It took them 5 or 6 years after leaving their old field to get anywhere with the acting though.

So...I don't know. You only live once.

Regarding the boyfriend. The grass is always greener, I suppose. Thoughts and feelings are ok...doesn't make them true..but if its constant and you think that you're not happy...end it. It's not fair to him or you to stay in a relationship with someone and be yearning for others...

The most important thing to remember is that you don't have to do anything forever. Very few people have the same job forever. You can do teaching for a few years, then move on to other opportunities. A lot of my teachers did it. My favourite teacher is a photographer in America now. Teachers are actually lucky, because most employers appreciate the skills and experience which you develop through teaching which means you have great access to a lot of other opportunities later.

Everyone gets cold feet sometimes. How you react is your choice, and all responses are valid.

Its normal to not know exactly what you wanna do and who you wanna be with at that age.

You are only 21.

Take gap year, travel around.. take some time to find yourself. Perhaps you will find you have a renewed passion for teaching, perhaps you will find another calling.

As for your partner/relationship.. there will always be someone better out there for you. That's just the way it is, but we love who we love and if we are constantly looking at others, then.. perhaps you aren't in love anymore.

Stop thinking career, work, money, and job. Think I just wat to do what I like and try everything until you find that thing. As for the boyfriend maybe hes not what you like doing either so take a break and see what and who you do like. Your 21 it's ok to be undesided do to serious lack of options and experiences.

Listen--nothing is wrong with you. I am nearing my 40s, and I often long for my younger years. Revel in your youth! It's perfectly normal to feel adrift, at various times during one's life. Don't be surprised if you feel this way again in your early 30s. My advice is this: finish your education first and foremost! You will always have that degree, no one can take that away from you. Don't be so hard on yourself, you are wayyy ahead of many others in your age group. Even if you don't go straight into teaching, at least grab that degree, you could use it for other occupations. There are many positions in showbiz that are not necessarily center stage. If you really do lack talent, then it probably isn't realistic that you will land the lead part in a Broadway musical, but what's stopping you from a behind the scenes job? That way you can experience the element you long for. If you're not tied down, after college is finished, move out to the big city, meet new people and enjoy your young years while they are here, because they don't last long enough! As for the boyfriend...who you were at 17, and who you are now, and who you will be at 25, 30, 35 are all different shades of yourself. Your interests, hobbies, belief system, and view points will shift, and/or outright change. Maybe you have outgrown him, and it's time to move on. Don't be shocked, if when you broach the subject, he feels the same way. You were teens when you got together, imho that's too young to settle down. Travel, explore, sample your dreams, and you might find exactly what you're looking for.

Solution -- set a goal that is a thousand years to the future and your current problems will disappear because you would understand that you are not a body.

you're only young, there is plenty of time to figure out exactly what you want to be.

Same except I'm a 21 yr old guy so I have a better chance, LOL jk yeah it sucks.

im 21 an all i wanna do is troll this site into oblivion... i set my goals pretty high

Figure out why you liked teaching in the first place and run with that idea.