Losing 1/2 your weight, and still being able to easily re-descend, does indicate that you are over-weighted.
At what stage in the dive did you lose the weights? More relevant: how much air remained in your cylinder at that time, and at what depth were you?
Whether you cylinder was full, or empty, would make a difference to the impact of losing the weight.. as the air in your tank has a weight value. Likewise, the depth is a factor, as this will determine the relevant buoyancy provided by your exposure suit.
The cast-iron test for weighting is whether you can maintain a hovering safety stop, with minimum reserve air in your cylinder. This means that your exposure suit is at its most buoyant and your cylinder weighs the least. If you can maintain the stop, then you have enough air. On that stop, assess how much air you have in your BCD. You shouldn't really need
any air in that scenario. If you have air in your BCD, then remove weights from your rig, until you reach the limit at which you can comfortably maintain your hover. That will be perfect weighting.
Problems with descent, in novice divers, are often linked with either; failure to fully deflate the BCD, anxiety causing heavier breathing (inflated lungs add buoyancy), not fully exhaling and/or subconsious movement of the feet (fining, whilst vertical) which provides upwards thrust.
I'm in the middle of writing a series of blog articles on buoyancy and weighting at the moment; you may find them useful:
Scuba Buoyancy Masterclass 4of9 - Assessing Your Weight Requirements