Pretty neato

 good spell

So if you haven’t taken damage after multiple turns do the temporary hit points stack?

Temporary hit points never stack.

am i the only one who thinks this spell is bit bad?

granted maybe im focusing too much on the temporary hit point part of this spell, and not the fact that it grants flat out immunity to the frightened condition, but the hit point part really does not scale well at later levels.

that being said, again, immunity to  frightened is actually really good. just wished the temp hit  points scaled every other level.

Probably? it is amazing, especially if you cast it on a barbarian or you've cast something like Warding Bond on the same target and up cast it with just a second level spell slot, 8-10 points of free healing every round in the mid to high levels is pretty amazing. 

When you cast this spell on yourself, did you gains firsts temporary HP instantly or on the start of your next turn?

As spell wording say creature target of spell gain temp hp at start of its turn.

Yup, and this weird, casting on yourself and rush іn to the fight with bravery - not a good option without some temporary HP). That's why i decide to homebrew the case when you cast this spell on yourself -  you gains temporary HP instantly after cast. Maybe this small addition put more use in temporary HP granting by this spell.

Its sounds logical after all caster spent an action

I hate the Frightened condition with a passion, and this spell fixes it. Possibly ignoring 50 damage (if you're taking a bit of damage every turn) is a bonus that makes it even better
Doing that to even more people at once makes this spell amazing for fighting dragons and other things with fear auras, if not every member of your party is a halfling cleric. You only need 1 hit point to live, and having that 5 repeating every turn on a group of people is really good when you're dealing with AoE's and groups of enemies attack multiple people. Every hit point counts, and if you're using a 3rd level spell slot to stop 150 damage and all Frightened conditions you've used a 3rd level spell very well
Screw the Frightened condition

It's good if so, but if immediately after your cast, the enemy breaks your concentration, then Frightened condition returns and HP don't appear, and it's kind of sad. No sight of spell at all. And if you have a few spell slots that is a bad choice either.
But at a high level, when concentration is not easy to fail, and you have more powerful slots - it makes sense, it will work cool that i totally agree. So i try don't forgot about this spell on the high levels)

Quote from PayDay >>

It's good if so, but if immediately after your cast, the enemy breaks your concentration, then Frightened condition returns and HP don't appear, and it's kind of sad. No sight of spell at all. And if you have a few spell slots that is a bad choice either.
But at a high level, when concentration is not easy to fail, and you have more powerful slots - it makes sense, it will work cool that i totally agree. So i try don't forgot about this spell on the high levels)

 Correct, if I'm casting this, it's usually not on myself, and if I'm a caster, most of the time, not being able to move towards an enemy isn't a terrible thing. It really sucks when you're a melee oriented character, and your option on your turn is to do nothing. It's much better when you throw it onto the melee folks, who are regularly getting hit by stuff. 
In my experience, whenever something hits a caster, especially at higher levels, their worry isn't whether or not they'll keep concentration. It's whether or not they'll live. Paladins are also usually very likely to succeed concentration checks once they pick up aura of protection, and if all else fails, you can simply cast the spell again

So underappreciated. It gives 5 temp hp, which replenishes every turn. It's like regeneration (7th level spell), but actually useful in combat. And it tacks on a useful immunity to fear and can be upcast to hit multiple allies. Heroism is probably going to "heal" more than any other spell until you hit things like, well, Heal.

Amazing on a redemption paladin

Is this worth grapping with Fey Touch? other options are Bless, Hex and Hunter's Mark

The spell is great on an Order Domain Cleric and even better if you have access to Meta Magic to Twin the Spell, especially if you have rogues in the party that cane make use of the Sneak Attack.

The biggest problem with this spell and up-casting it or twinning it, is that it is a TOUCH range. Your party members need to be close to one another, and you need have 5-feet next to each.

Otherwise, extra 5-HP buffer per turn adds up VERY quickly in prolonged battles

Quote from Xidien >>

Is this worth grapping with Fey Touch? other options are Bless, Hex and Hunter's Mark

 

 Depends on your BASE class. If you are a support class, then it depends on what other support spells are already in your inventory. I would say yes, for most support classes. If you are a Warlock or blaster type, you'll want to keep your concentration for damaging spells.

Even at higher levels, the temps return every round. So it's 5 points of (pre) healing on x number of people at start of each of their turns. It adds up!

Do temp HP save against dying? Or help vs. unconsciousness

Nope, granting an unconscious creature temp hp will not bring them back to consciousness, only healing can do that.