Which Products should I buy for tangles/more softness for my birthday?

Hey! I had some questions regarding some products I want to buy myself for my birthday.

My hair was always long and fine (2a/2b). I started bleaching and coloring it (semi-permanent dye) 2-3 years ago. I have severe vitamin d deficiency and slight iron/b12 deficiency and hypothyroidism (My nails are also extremely brittle, they break and chip every day). I am now taking medication/supplements and am waiting for results. I have other illnesses but I don't know if they are relevant here.

Products I use: loreal metal dx pre-/shampoo, K18 (I tried olaplex 0. and 3. and didn't like it but I love the 7.), with conditioners/masks/leave ins I try to use more hydrating products and every month or so cer-100.

Some Redken products I've been thinking about: all soft conditioner, acidic bonding concentrate, extreme cat treatment, extreme anti-snap treatment

My current problems are: -not enough shine/softness -constant tangles that lead to breakage

My hair felt and looked really good one time when I used the k18 mask normally + after my routine as a leave in. I heard it isn't as effective if you use it after a conditioner and I can't skip conditioner longterm or use it twice (it's too pricey) Is there a way to give me similar results with other products? My hair felt more soft/fluffy and had more shine and I think it helped with the tangles. Also washing my hair more often prevents tangles/breakage for me.

If you have any input or tips I would really appreciate it ❤️