Had to have my DeX steroid reduced to 20ml per day mon /Tue because of racing heart.i managed 2 weeks on 40ml .very scary at the time especially being on my own..At the moment the treatment is worse than the condition. 
Hi J19 and welcome to this corner of the Community although I am always sorry to see folks joining us. I noticed that your post had not received a reply yet so thought I would drop in past.
I am Mike and I help out around our various blood cancer groups. I don’t have Myeloma but was diagnosed in 1999 with a rare, incurable but treatable type of Skin NHL (CTCL) Stage 4a so although my blood cancer ‘type’ is different I know this journey rather well.
I am sorry to read about the scary reactions you have had to some of your meds. This happened to me during my second Stem Cell Transplant in Oct 2015 so I am now on heart meds as I have A Fib, but it's all under control and living life along with this bump in the road.
The Macmillan Support Line is open 8am-8pm (timings may differ across services) 7 days a week on 0808 808 00 00 or via Webchat and Email too. This service provides cancer information, practical information, emotional support, benefits/financial guidance or just a listening ear. You may also find our Ask an Expert section helpful but do allow a few working days for a reply.
Talking to people face to face when on a cancer journey (patient or family) can be very helpful but during these strange times it’s not that available but do check to see if any Local Macmillan Support in your area has opened up.
Do also check out for a local Maggie's Centre in your area as these folks are amazing and they do run online Haematology Support Groups. Ourgroup covers the Highlands so a large area but it's great to be able to talk and support others especially as many live in remote areas....... and there are a few folks in the group with Myeloma
Always around if you need further help in navigating the community.
All the very best.
