to OP.
I lost my mum nearly three years ago. I still miss her hugely. I think people assume grief has a time limit but I think it comes back in different forms and for different reasons, as your life goes through new stages there are new reasons to feel the loss of a loved one.
Only you know if you would benefit from counselling or not, but I don't think what you describe sounds necessarily problematic. If grief is intruding on your life in an unmanageable way or stopping you doing the things you want to or need to then you might need extra help. If you just feel sad (even incredibly sad) from time to time but you are still living the life you want then I would say choose the strategies and support that get you through those moments and know that grief and sadness are a normal part of life.
Fwiw I have found reading this thread comforting to know others are still managing their loss, so thank you all 
And huge thanks to PP who posted the article about grief, it's a very complex and misunderstood thing.
I may be projecting my own feelings here (and I don't want to derail the thread!) but I always find comments such as, "Im sure none of your parents would want this for you. It's not healthy to grieve this much after a long period of time." really unhelpful.
I don't want to mount a personal attack on @silverbell but I find this kind of comment is often made in a bid to be helpful or comforting and I find it really insulting. I want to explain why in the hope that people might be more aware of how it can sound to someone who is bereaved.
- Obviously my mum (or pretty much any loved one who has passed on) didn't 'want' people to feel sad. She was not a psychopath or a sadist(!) and of course she wanted her children to have fulfilling happy lives. You're not telling me anything I don't know.
- I think (at least in my case) she would completely understand and respect that we grieve when a loved one dies. During her terminal illness we sometimes talked about when she cared for my dying grandparents whom she still missed. Part of our relationship included supporting each other through the bad times as well as celebrating the good ones. So I feel irritated when you suggest you can guess what she would think about my reaction.
- Your words imply there is a right way to grieve, and that I might be disappointing or betraying my mother's memory by not conforming to what you assume she would want. There really isn't a right or wrong way to grieve and at vulnerable moments, the last thing I need is to hear that I should feel guilty that I'm getting it wrong.
- It implies we choose to feel sad. It's like reactions to depression when people suggest someone can just feel better. I don't wake up in the morning and I think, "I'll be sad today because my mum would want me to." I get up and live my life, but sometimes I meet a reminder of what I've lost and it hits me. I'm not choosing to feel that way. Forget what anyone else thinks, I don't want to be sad. But something very very sad happened to me and it doesn't just go away.
- We are all unique individuals with different experiences, strengths and weaknesses. Some days I can manage what seem to be very heavy burdens, other days something apparently small tips me over the edge. You have no way of quantifying my pain and therefore no right to judge its appropriateness. (imo this is true for all kinds of emotions, not just grief)
Of course there are people who need extra support (not necessarily counselling!) to deal with complicated grief that is having serious effects long after the bereavement but I believe even for them suggesting that they should get over it because "that's what X would have wanted" is unhelpful.
Sorry if I have gone off topic...