Your T levels are supposed to climb right away after a topical gel application: the T should be absorbed right into the blood stream. Two comments though:
1. Some of the gels (Androgel/Testim) seem to be poorly absorbed and relatively low concentrations, so that many men cannot significantly raise their testosterone with them. (Compounded testosterone can be much better.)
2. Even if you boost your T significantly, it can take weeks or months to feel the difference. There are many reasons for this, but the summary is that the testosterone is literally "healing" your tissue. The internals of your penis are improved, receptors in the brain and muscles are rebuilt, blood cells, etc. - the list could go on and on. But this takes time, so you must be patient to see results.
Also, I try to always give this warning: be very careful to make sure no family members come into contact with the topicals. Keep the area covered with clothing and be diligent to wash it off later in the day per your doc's specifications. (From what I've seen, that's usually about 4 hours later, but ask him/her.)
Finally, one last thing: 225 is very low. That's actually hypogonadal. Did you get this reading before or after you started the gel?