Yes it sounds like a hemorroid, but the hemorroid won't be the cause of your constipation.
With you straining on the toilet that is what will have caused your hemorroid.
You need to get your stools coming out softer, by drinking more fluids and eating more fruit and fiber.
Hopefully that will cure your constipation and the hemorroid will eventually go away.
If the hemorroid gets to be annoying it is worth a visit to your doc, who will prescribe a medication to fix it.
Hope this helps