Okay, you should remember when cooking with Indian flavours, unless it's a proper type of sugar, don't add anything to sweeten it. Orange peppers are incredibly sweet compared to the other flavours and using correct chillies in curries is a delicate process that takes a while to master. Now it's been almost two months since you asked this but if you do face the same issue again, fry some garlic and ginger in olive oil and if you have any, curry leaves (can be difficult to find in some countries) - take it off the heat and add a few tablespoons of yoghurt mixed with a tablespoon of cornflour. Pour all the contents of the pan into your curry and see how it tastes. It might need more salt at this point - add to taste.
It will not taste like a restaurant's - it'll taste like what it is - ready made spice mixes with a bit of a love.
Substitute one star anise for the curry leaves if you can't find any. In fact use both if you want. I do.it gives it a butter chicken flavour which is what I think you ought to go for as chicken tikka masala is really just a mix of some tikka spices and butter chicken. Give or take some awesome.