Weight gain/Water retention and Tamoxifen

I have been taking Tamoxifen since November 2011 and have noticed that it is very hard to shift the excess weight that I put on whilst undergoing chemo / radiotherapy. Just wondered if anyone else had the same problem – have been dieting and upped my exercise but nothing is making a difference. Not sure if this is caused by water retention as my fingers are swollen and at the moment I am unable to get my wedding ring off. Has anyone tried water tablets – just wondered if they would make a difference Hope everyone is OK xxx