This is an issue on almost every instrument.
There is a guitar teacher named Jamie Andreas, who focuses on minimising tension from the very beginning of learning. Her approach is to practice dead slow. I think this will work equally well on the violin.
Finger a note on the fingerboard. Don't play it yet. Check your entire body for tension. In the shoulders, in the arms, in the hand, in the fingers - everywhere - and work to relax all those places, while still applying the minimum of force necessary to hold the string down firmly.
Only when you're satisfied that everything is as relaxed as it can be, should you bow (or on a guitar, pluck) the note, again concentrating on relaxed muscles.
Now move on to the next note -- many seconds having passed -- and work on transitioning from the first relaxed position, to a second relaxed position, without going through a tense moment in-between. You need to learn how it feels to be in those relaxed positions, so that you can reproduce them at speed.
Since you have two years experience, this will be frustrating and you will be tempted to go faster. But resist that urge, and go ridiculously slowly at first. When you can play an arpeggio in a completely relaxed manner, one note every 10 seconds or slower, that's when to try speeding up.