I will disagree with the most upvoted and accepted current answer for the first part. As a DM, really, if we want to, our ghouls are going to get to those Bard and Wizard. And that's without any Deus Ex, particular hate or anything. Ambushes happen. Ambushes happen A LOT in CoS.
I have DM'd CoS and, specially in Death House (which is not the scenario you are probably currently playing as you are already 5th level, but nonetheless) it was pretty common for the Bard to be attacked. As I've mentioned in a comment, I can't figure out where you are, so I'll have to focus on a general situation (i.e. no specific knowledge of the map/scenario).
Obviously you should be constantly trying, as a team, to be in a formation where the squishies aren't being targeted, but that is not always possible. I will proceed with my answer as if things went bad.
These are two basic actions for combat. Disengage allows you to get out of there. Dodge helps you to get less damaged if you are being focused. Dodge essentially increases your AC by 5. You should then use this turn to regroup with the rest of your party and have a better formation where you aren't the one tanking.
I will paste the Minor Illusion entry from Treantmonk's Guide to God Wizard (google docs link). By the way, I recommend reading this guide for some good uses of spells, even if you are not a Wizard yourself. He also focuses on a Support Wizard, by the way.
Minor Illusion: They made illusions a forever use Cantrip? This should ALWAYS be on your list. If you are not overly creative, let me give you a couple examples that make it worth it all on their own. 1) Remember Blade Ward when I said “get out of dodge instead”? Make an illusionary stone wall between you and your enemy and back away. 2) Put yourself in an illusionary wooden box and cast spells out of it 3) The illusionary hiding Halfling with a shortbow makes a great distraction (to all those who say, “the spell says “object” Treantmonk, not “creature”), fine, it’s a hiding Halfling with a shortbow that’s been petrified.
My comment: Yes, a petrified creature is still a creature. Change that to "a statue of a halfling with a shortbow" - happy now?
Obviously this depends a little on DM Fiat, but usually it's fine. Ask them beforehand anyway.
Well, I'm not sure you wanted us to criticize your choice on spells, but I would easily change Phantasmal Force for Invisibility. Mainly in CoS. It's a great spell for both scouting and a free pass out of jail when you are in trouble.
Keeping the criticism on the spell selection, Thunderwave is a great spell for shoving enemies out. This might help when you are surrounded, so you can get away easier. This one might be harder to get a place to fill, though. Check if any of the other 1st level spells you have isn't being too useful.
Simply hiding (even before the fight)
This one depends on the mentioned scenario (which I don't know), but usually you should be able to find places to hide. Really, this is probably the best approach that doesn't spend Spell Slots and you probably won't be targeted to begin with. If you are in a place you know you are going to have fights constantly, unless it makes no sense for your character, be paranoid, constantly hiding. This way, even if enemies ambush you, they might not spot you and so they won't target you.
Erm... Get better armor?
It seems you got a +2 or max +3 modifier in Dex. This means medium armor helps you. I would recommend against using Heavy Armor despite the better AC because you are most likely going to be the scout of the team, unless the Fighter/Rogue does. This means a) You should get Invisibility b) You don't want disadvantage in Stealth.
I would honestly go with Multiclassing into Cleric. This won't hurt your spell slots (as Cleric's full caster as well) and will only delay your spell selection for higher levels by 1 level. If you finish CoS by 10th level (usual), you won't even notice any end-game difference. This should be a way better option than getting the Moderately Armored feat.
Note on chain paralyzed
Welp, if you got to this point, there isn't much you can do. It stops you from moving, using actions or reactions and gets constantly hit since they attack with advantage and even crit.
DON'T GET TO THIS POINT. If you did, you rely 100% on your teammates.