Ty for all advice. My situation is way better now, because I don't generate as much threat as before cause I only place HoTs on Tank. Also Surgical Probe and Healing Trance made difference. Often there is still 1-3 mobs on me but with bubble I can manage. If situation starts to seem too bad, if there is more than 3 mobs on me I can use Cloud Mind, even if some tanks and DPS seem not like it. Luckily most of them accept apologizes:-)
Good to hear things are improving for you personally, although it does sound like it's you that's finding your feet rather than getting better groups. You should NEVER have to apologise as a healer for getting mobs off you, they shouldn't even be on you in the first place.