Big big sympathy! I suffered/am suffering with this too! I found that getting some prescription cream from docs/suppositories helped ease it (still suffering 5 months down the line - sorry). I know it's a cliche, but try to eat loads of fibre/freash fruit/water as this really does help.
You should go and have it lanced in the A&E asap. Don't bother with the creams. You have to be able to sit down, rest and recover fromthe delivery. You'll have to have a bm sometime soon, after all. They will give you a local anesthetic and lance it -- believe me, I've done it after 9lbs baby was born. I had what they said was a thrombosed hemerrhoid -- and I thought I could cry for relief when it was gone. I couldn't even sit down in the car all the way to the hospital to get it done, and I could have ridden a bike home again. Felt SO much better. Hurry -- you don't have to suffer like this.