I'm not understanding either so let's visualizes this a bit and briefly review the basics. Here's the numbering of pentane. Since it's unsubstituted and has no distinct differentiation at any point you can begin numbering from either end.
However as soon as you add a substituent(s) you need to consider which side is the start and which is the end. Take 1-chloropentane. Since the chlorine as been added to first carbon, the opposite end can no longer be 1 and must be position 5.
Cl-CH
2-CH
2-CH
2-CH
2-CH
3 = 1-chloropropane
If you want to add a second substituent to 1-dichloropropane and make it, for example, 1,4-dichloropentane then you'll have to follow the numbering based off the "parent" 1-chloropentane.
CH
3-CH
Cl-CH
2-CH
2-CH
2-
Cl = 1,4-dichloropentane
The molecule you wrote out is actually 1,5-dichloropentane. This is because one of the chlorines, in this case it's irrelevant which, is your first position and counting out to the next one it's on the fifth carbon.
Cl-CH
2-CH
2-CH
2-CH
2-CH
2-
Cl = 1,5-dichloropentane
I hope this clears up any confusion. If I misunderstood your question let me know.