well, first let me tell you, i have been in public school for 8 years, so i know what im talking about when i say: it sucks. so bad. so as for you issues though:
1. you have no friends- do some sports or something. find out what it is your interested in and go do it. you will find tons of friends (as long as you're some what out going and talk to ppl) soon enough.
2. the pressure of you mom- i think you are over exaggerating just a tad. but still, what you should do is, next time you feel her pressuring you, tell her. i know, easier said than done, but just be like "oh my gosh, mom, stop that. it makes me really nervouse (or enter other emotion here) when you do that. you make me feel like i have to be so perfect. well, i can't mom. i know you want whats best for me, but no one can possibly be perfect. im sorry, but if you could just relax a little, that would be great." because honestly, i think that she will help you more if she lossens up a bit.
3. u need to tell her you r bored w/ homeschooling- just tell her that. tell her your getting kinda bored with the agenda ever day. maybe you could try doing some more fun activities. for science look up some experiments on the internet that would be easy to do and are relivent to what you are currently learning. i really can't think of any thing for other subjects, but im sure you'd be able to come up with something. you could go to the zoo (sounds kinda childish, but it is WAYYY better than sitting at home doing work sheets and stuff), or you could go to different historical places (for example if you are learing about the american revolution, you could go to john jay's house), if its nice out, take class outside for the day. mix it up a bit. isn't that kinda the point of home schooling. to A. get a better edgucation, but also B. use different methods of teaching, including field trips and just different fun activities.
4. she thinks public school isn't safe- well that really depends on the area you live in, but that can be very true, or totally incorrect. some schools really are not the best learning enviorment for kids. i do side with her only on the fact that my school has about 50 bomb treats a year, and my school is in a very nice, small town. i don't even wanna know what happens at other schools.
5. your sitting for 5-6 hours straght- break up your day a bit more. do 2 or 3 classes, than have a break, than back to your classes. if your mom doesn't go for this, make her a deal. instead of just having a break to do nothing, read a book, or something else fun and educational. if you can't do any breaks, at least make an excuse to go to the bathroom ever 3 classes or so. that way you atleast get up and walk about 10 feet. oh, and than back. vacation of a lifetime, im tellin ya.
6. i just highly sugest, that what ever you do, what ever you want from your mom, don't yell at her. tell her as maturely and politely as possible about whatever the issue is. i also remcomend staying home schooled. you don't sound like your all that young, so you must only have a few years left of schooling ahead of you. and being home schooled, you will defenetly get a better education, and its just a better expierience in general. most ppl say "oh if you're home schooled you don't get the social interaction that you need". well nobody needs to be just walking down the hall, minding their own busness and suddenly some guy they don't know walks up to them and pulls up their shirt and takes a digital picture of it, and send it to everyone in their contacts, and than suddenly everyone is calling you a slut bc everyone thinks you took the pic yourself to get guys! so yeah. public school sucks too. so no matter how you put it, education only leads to crap, crap, and more crap. untill the very end, when you get the job of your dreams, and your just like =D OMG!
so yeah. good luck.