First of all, antiobiotics are notorious for causing tinnitus, as most of them are ototoxic and activate glutamate receptors in the inner-ear which basically leads to a nerve- cell slaughter.
Secondly, have you taken any time to research the common causes of the inner-ear dysfunction that leads to tinnitus. Aside from antibiotics and hundreds of allopathic medications that alter the body's natural path of function (including Advil and Aspirin), there are many ways in which the symptom (or alarm) of systemic health imbalance known as tinnitus can develop.
The good news for you, is that many of them are directly related to decisions you make each and every day, from what type and quality of food you eat, to how you react to stressful situations and the environment you live in.
Since you've repeatedly referred to your persistent cold, I'll ask you this: do you know why you're body is unable to ward of this virus? It is supposed to have immunity to it and not contract it in the first place.
Based on my understanding of how the body works, if I couldn't kick a cold I would first off all decide that this is a sign from my body that my immune system is severely compromised.
Considering this (and a lot of other things I don't have time to go into) I would not take antibiotics which make me even less immune to colds and actually cause what's called candida yeast overgrowth in my intestinal tract, which directs all my body's attention away from taking care of things like colds and keeping my ears functioning properly.
Lowered immunity means that my body is less able to hang onto vitamins and minerals, especially the mostly water soluble B vitamins, zinc and magnesium, deficiencies of which is known to cause tinnitus.
I would also consider that sinus infection, which I may have if my sinuses have been clogged for months on end, is known to effect the flow of blood to and the function of the cochlea and thereby cause tinnitus in some cases.
Knowing what I now know, and admittedly this is just a springboard to higher truths that can only be discovered through proactive remedies efforts, I would do everything in my power to rebuild my immunity via organic, fresh fruits, vegetables, grains and meats and perhaps some herbal formulations from my naturopath and doing the Candida cleanse from candidacleanout.com.
More importantly I think, I would work on emotional stress reduction by listening to Dr. Leonard Coldwell's stress reduction CDs, building my dreams and defining my chief aim in life, filling my mind with positive thoughts each day via books and CDs (I recommend Your Wish is Your Command by Kevin Trudeau), walking in the sunshine each day, laughing and generally changing my physiology to match my desired psychology.
I'd also take some standardized (to the specifications of the Commission E in Germany, who has approved it as a tinnitus treatment) organic ginkgo biloba extract each day (240mg), as well as some black cohosh and include foods high in the vitamins and minerals I mentioned earlier that are linked to tinnitus.
From there I'd just keep a journal of my results and make adjustments as my cause-profile becomes clearer. But I would be certain that as my health improves so will my happiness and the combination of improved health and happiness can't help but reduce and eventually eliminate my tinnitus.