Can I make my code closed source? Or Do I have to make it open source?
In general if you use unmodified LGPL-licensed libraries and dynamically link with them, you can use any license you want for your own code. If you redistribute these LGPL-licensed libraries then the LGPL applies to these libraries of course.
There are no issue with linking with OpenSSL.
For OpenMP, if this is code that is part of the GCC runtime, then this is likely not GPL-licensed, but rather would likely be using the GPL with the GCC exception which is essentially equivalent to the LGPL.
If instead this is plain GPL and you are calling it from your code, I personally would consider the GPL to extend to your code.
I only included omp.h in my program [...] omp.h states that "This file is part of the GNU OpenMP Library (libgomp)", which is GPL 3. Then in next line it mentions- "Under Section 7 of GPL version 3, you are granted additional permissions described in the GCC Runtime Library Exception, version 3.1, as published by the Free Software Foundation." The 3rd post in this link openmp.org/forum/viewtopic.php?f=3&t=474 also confirms it. So can I use it as LGPL then?
You can use it under the the terms of the
GPL 3.0 with GCC Runtime Library Exception, version 3.1, not as LGPL.
But IMHO the GPL with this exception is a better license than the LGPL. For instance, it is clearly allows for any kind of linking: the LGPL makes a distinction between static or dynamic.
I would go for it!