As someone who has been wearing a suit and tie to work every day for a a very long time ....
I'd need answers to several questions - like, is the sweating a new thing, or have you always perspired a lot ? Sweating that is more profuse than you are used to, might be a sign of something else. Are you particularly anxious at work?
Also what kind of shirts are you wearing? Natural fabrics - ie, cotton are best - although a cotton-rich polyester blend is very good too.
Assuming nothing untoward, it seems to me your Mitchum unscented gel isn't working for you. I'm a big fan of Clinique Skin Supplies for Men antiperspirant-deodorant stick.
If you can't find an effective antiperspirant-deodorant, consult your pharmacist or doctor. Stronger treatments are available over the counter. Alternatively, your doctor may recommend a cream or gel containing aluminium chloride that is applied to the skin to reduce the activity of the sweat glands.