Again Stefan,
I think it's good that you know that you did something wrong and the fact that it might have some repercussion (consequence) because of it.
But, to run away or completely hide whenever you are faced with difficulties is not a good habit to learn.
So, the best way to deal with it is learn from your mistakes and never again overfeed Clea.
As far as your dad goes, just do your best in trying to convince him (provide him the scientific papers and so on. If he still refuse to listen about how bad compact uvb is, then find a better way.
Clea is your chameleon, am i right? It is not your dad's. So, essentially, you have a defenseless creature that is depending on you for her survival.
The responsibility falls on YOUR hands.
Perhaps try to "earn" money to buy a linear uvb (sell lemonades, cut neighbor's lawn, clean the gutter, or anything..).
This will show your dad that you mean business. That you are a responsible kid and will do anything necessary to protect your responsibility (Clea).
I believe no dad in this world cannot be happy/ proud seeing his kid somehow "man up."
The idea is not giving your dad a lecture about responsibility. But, living by examples.
Lecturing will fall into deaf ears. I know I would feel annoyed if my kids (who still cannot support themselves) are lecturing me about responsibility.
See this in a different perspective.
I cannot speak for your dad's behalf.. This is a pure conjecture of my own.
I know that I will give my kids option of owning a pet.. and there will be problems that I will let my kids solve on their own, since imho it is the best way to teach my kids the meaning of the word "responsibility."
I understand that you are sad. But, don't let that sadness blind your common sense. If every time you are facing difficulties, you run.. or hide or quit.. then you are missing a heck lot of opportunity to learn and become a better person..
Hope that helps.