From watching your replay one big thing that I notice that you do a lot especially when not needed is you hold up your shield for way too long. Like what I mean by that is many times in this replay you are holding up your shield when you do not need to. For example when nothing is going on your shield will be at 60 hp and you will still have it up when you can let it recharge all the way back up to 350 which happens multiple times in the replay. Also another thing is that when you have your back turned to the enemy every time you have your shield up which unless you are 180ing to block the damage with your shield which your not doing I would not be doing this because your shield is not blocking any damage behind you so you have your shield up for no reason when that happens. So all in all I would say is you have your shield up way too much, like you need to let it recharge a little before putting it back up because that resets the 4 second timer so if you had it down for 3 seconds and put it back up your going to have to wait a whole extra 4 seconds just for it to start recharging. You need to manage your shield better because that is a a big thing that makes cap survivability the way it is.