Welcome to the forum!
I hate to be the bearer of bad news, but on another forum I visit, that lens was voted the worse lens ever made by Canon. I would look to replace the lens first and the replacement should be based on what you like to shoot and your budget.
Do you like to shoot true macros or are closeups more what you have in mind. A lot of lenses can shoot excellent closeups and some even say "macro" but unless the lens can shoot at least a 1:1 size, it's not a true macro.
I rarely use a tripod when shooting macros and can never recall using a remote shutter release when shooting them. If macros are your primary interest, I'd go for a new lens.
Just to show the difference between a macro and a closeup, here are a couple of shots for comparison. A tripod was not used for any of these shots.
This is a macro - taken with a Canon 30D and a Sigma 150mm f/2.8 macro lens.
This is a closeup - taken with a Canon 30D and a Canon 135 f/2L lens.
Closeup can be taken with just about any lens and if you want to get even tighter shots, you can crop or add closeup tubes.
This is a crop of a shot taken with a Canon 30D and a Canon 100-400.
This one was take with a Canon 30D, a Canon 85 f/1.8 and a closeup tube (no cropping was necessary).
Hope this helps. If you'd like help picking out a lens, let us know your budget and what else you like to shoot.