Tamoxifen side effects

Hi to all the ladies on tamoxifen, I have been on tamoxifen for over a year now. I was put on it (instead of the AIs) because I already have osteoporosis. I did do a stint on the AIs but I was turned into a cripple basically overnight. I thought I was going okay on the tamoxifen but in the past couple of months I have had a few problems, pressure in head, heart palpitations, shortness of breath and pains across chest and back. I have been to ED several times in the past week as I have had a couple of these 'episodes' where it almost feels like I am having a heart attack. I have now been told by the oncologist to have a spell off Tamoxifen to see if these problems subside. Anyone had these problems? I know a lot of topics have been started about Tamoxifen but some of the knowledge is so far back I thought it may be easier to start a new thread. All the best Muriel p.s. oh add nausea to those symptoms