Recommendations for complete blackout blinds that aren’t hundreds of pounds and for eneven window spaces?

I brought a blind from ikea this year, its good fabric fully blackout however the light gets in around all the edges as it’s not fitted. I also get lots of damp in my room so it’s now covered in mould as it touched the window. I’ve been looking on Blocout website and I wouldn’t had minded paying the £120 for fitted blinds but then they nocked up the price by another £150 because they are slightly uneven. Surely they must be other places that do them that arent so pricey. Also ideally I don’t wanna have to wait weeks for postage if possible as it’s really fucking up my sleep it’s causing my body to have issues.