Hey, Crucible can be a bit of an interesting one, with the sheer amount of builds and meta's it can often be quite a challenge to break through and improve. Amour mods have an effect to a certain extent, you will be able to recover health fast with more recover mods however these mods will not turn you into a tank or speedster by no means. There are multiple ways to gain an overshield and some overshields are quite strong, a common thing that is happening now is Titans using the void subclass and using the aspect that gives you an overshield when putting down a barricade. This is quite a strong play and can often be hard to counter, if you are not hitting headshots then your chances at surviving a fight like this are slim. Understanding weapons is also a big factor I would recommend, if you are not confident with Hand Cannons yet then I would suggest using a pulse rifle as they reasonably easy to use and are quite effective and you can eventually work your way up to using a Hand Cannon. There are many videos out there showing you new builds and meta's however I can recommend watching streamers playing the crucible if you want to learn tips and tricks. The best thing to do is to keep on practising and one day it will click.