Does complaining to a created being constitute a lack of trust in Allah Almighty?

There is no harm in you speaking with experienced individuals and those who offer advice about your problem, for this is among the legitimate means that Allah has prescribed, and it is not a sign of distrust in Him. You may find a solution or guidance with them. Consulting with people of sound judgment is a legitimate matter, as stated in the Almighty's words: "And their affair is [determined by] consultation among themselves," and "And consult them in the matter." The Prophet, peace and blessings be upon him, consulted his companions in his private and public affairs. Therefore, seek advice from those you trust, have a good opinion of your Lord, and know that all good is in His hands, and that His decree for the believer is entirely good. So, be content with what He destines, and trust that His choice for you is better than your choice for yourself.