If I understand your problem correctly:
1. each 4 lines has a key for e.g.

5:1:1934:1185#CGATGT/1
[download]

2. with values:

sequence: GTCATCCTTAATTANCGTATGTGCTCTTCCTNCNNNNNNNNGCTGCTANTTATTTCTNNG
+CAGCTTTGCT
Its ascii code:
acdad`^ddd^aa^B_\VZZfcfccaffBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
+BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB<br>
[download]

It might be easier to grow a Hash of Array and access random keys to print the lines: e.g.

my %HoA = (
             5:1:1934:1185#CGATGT/1 =>[
                                        GTCATCCTTAATTANCGTATGTGCTCTTCC
+TNCNNNNNNNNGCTGCTANTTATTTCTNNGCAGCTTTGCT,
acdad`^ddd^aa^B_\VZZfcfccaffBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
+BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB            
                          ]
              
           );
[download]

NOTE: untested