Feeling So Unwell But No Fever, Please Help?

For the past 2 weeks i have been having mild symptoms of cold, feeling very tired, having chills on and off, and swollen glands in my neck. At first i thought i am going to get a cold as i always have these symptoms one day before cold/flu gets me, but not this time.
Yesterday was bad and today even worse, i feel awful, i thought i had at least 38 C fever but after measuring several times it shows i don't even have a low grade fever.
I am so scared this is lymphoma or leukemia as the symptoms are the same: tiredness, feeling unwell, no fever, swollen neck glands...I am seeing my GP tomorrow, but wanted to know if these symptoms could be caused by something else, less dangerous?
Also could stress/anxiety cause this because i have been going through hell for the past month or so [ family issues ].
Hope someone can help.