Are the struts stuck at full extension? Is there any travel up and down? I have had a lot of experience with bulsteins and they just suck for me. Other than that it sounds like the springs in your new replacements are for a heavier vehicle... unless those bulsteins are stuck.
If it's not the struts you can swap the springs from your original to the new ones and get your ride height back to normal.
95 E34 530I V2.17
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