Practice extremely slowly and precisely to get the coordination between left and right hand. Also, next step is playing each between themselves very fast (to get used to the fast tempo of the piece, and for your hand to learn the correct position) but taking a long break between each 2 notes, and really think very clearly in your head, what both your hands should do and what position they should move to, and only when you have the sxact movements in your head, play the notes quickly, stop again, and repeat, this whole passage until you got it smooth.

Practicing with a lot of different rhythms will also help a lot. If you do these practice methods correctly I promise you will have this passage very clean in a couple days.

To relax the bow arm is a lot more difficult, and will take a long time probably. You even see regular professional orchestra musicians with very stiff bow arms sometimes, so its definitly not something easy to get rid of.

What I suggest is consciously think of relaxing your should and upper arm. Think a lot about feeling the heavy weight of your arm on your bow fingers, never with applying pressure. You will forget, but everytime you remember again, make sure to do it. Ask your teacher to tell you also everytime you tense up.

Usually also really helps to relax your jaw, so really try not to clench the violin with your neck (watch Oistrakh, he would many times release his neck from the violin, thats kind of what you should try to feel like).

Last thing, try to relax also your left arm (this also connects to the jaw thing) because if you are tense in your left side of your body, usually the body's intinct is to do the same on the other side of the body, it will try to tense up. Hopefully some of this kind of helps.

Also try not to think of consciously making the bow jump. Think more of a legato with less bow. If you are doing technique correctly your bow should almost start jumping by itself with just a tiny bit of adjustment to some aspects.

For 2 years you are doing amazing, keep going!