Welcome to the board - and yes, there is ample reason for hope.
What you're experiencing very much seems like a die-off reaction as you suggested. The garlic you took would definitely make them very unhappy indeed - especially roundworms - Ascaris - which I believe is what's in your picture.
Its hard to compare my own experience of what's worked to yours because mine was a fairly um thorough infection, but DE certainly worked for me, so that's definitely a good start to your treatteam programme.
As far as dealing with the die-off, folk on here have had success with milk thistle, l-ornithine, plenty of water, lots of fibre to keep your digesitve system flowing along, vitamin c, b-12.
Mizmac has a pretty solid protocol you might wish to try, or if you want to take a more hardcore pharmaceutical route look up mattk3's posts.
Naturally recovery time depends on the severity of your infeciton but at the end of all this you are very likely to undergo a remarkable transformation in your level of energy, motivation, mental clarity and sense of wellbeing, so there's absolutely soemthing awesome to look forward to...