Junior year is being really difficult for me?

it's only been close to two months and i've already had a breakdown. Chem. is so hard and my teachers terrible i studied for three hours for a test and got a 62. Also, im in french 3 which is also really hard. ive never done well in french but this year i feel like im bombing everything. In the beginning of the year, i had a too stressful schedule which left me one hour a day for homework/studying/eating/showering. i just quit one activity so im a lot more free to study better but im still nervous. Im afraid i'll fail my regents and have to repeat the year. ive cried so much this year due to stress and already missed two days (once i was sick and one day i was hysterically crying to my mom about how i couldnt handle the stress) teachers expect so much like your their only cl. my french teacher gives well up to an hour of hw each night and will give us 2 quizzes and a test all in one week. trig is sooo hard ive always done bad in math but im really trying to maintain a ping grade which i have all these years. my mom thinks its all my fault im doing bad and i dont study enough but i study whenever i can i just avent had enough time till now. also im stressing over the sats because on my psat i only got a 540 on verbal and 430 on math and 460 on reading and i was hoping to do better. if i do bad one quarter (70's 80's, couple of 90's) but improve a lot 2nd 3rd and 4th, what will colleges think? (im thinking of a good college. not harvard but not a community)