So, infected are very, very hard to make work well because they are so expensive.
I can give you advice but I want to make sure it's pointing in the right direction, because I'm not really sure what your priorities are.
Banshees pay through the nose for some very small stat boosts, some very, very serious drawbacks, and a few very good abilities (Fear, Mist Form, Essence Drain, and Regeneration). Note that you're also capping your Magic one lower to be one which is a serious hit. That said, they are just weak, not awful, and you can make a playable Banshee. But it sounds like you picked Banshee as something that met some criteria, rather than because you specifically wanted Banshee, so I want to warn you about this.
If you do want to play an Infected, I would think about Nosferatu. They look more expensive, but actually aren't; including the difference between Human and Elf base, they pay 55 more points, but get 80 more points of stats, and on top of that they get some notably better powers. The big thing is that unlike Banshees, a Nosferatu can lean almost completely on their innate powers to be effective.
If you just want Regeneration, a generally better (and less wierd) option is to be a Possession mage, get Invoking and Channeling ASAP, and have a Great Form Plant Spirit possess you. This gives you Regeneration, among other things. It does have the drawback of not kicking in a few adventures down the road when you can afford the two initiations, but it's got a lot less drawbacks than Infected and doesn't require as much screwy stuff.
There's also a funky option where you make a mage (either Materialization or Possession), pick a tradition that gets Plant, plus one of Guardian, Man, or Task, Invokes a great form Plant and a great form Guardian/Man/Task spirit, has the second spirit Endowment the Endowment power to the plant spirit, and then has the Plant spirit Endowment its Regeneration power. This is harder to pull off - you have to be able to get Great Form spirits of two types, which means you can't just lean on Specialization - but it doesn't make you Possession-dependent, and it has the side effect that you can actually grant Regeneration to a bunch of people, not just yourself, which is nifty.