Some very useful links for you :
Haemoglobin - 13.8 g/dl . range 12-16
Your result is in range, suggesting you are not anaemic, which is amazing given your other results.
Ferritin is 14.7 micro g/l . low. Range 15-300
Your ferritin (iron stores) is dreadful and suggests you have very low iron. You probably need to start taking iron supplements, but it would be a good idea to know your serum iron level first, just to double check. I am only guessing at your doctor's motives, but I assume she is ignoring the low ferritin because you aren't anaemic. It isn't a good reason, in my opinion. Most people feel much, much better with higher ferritin. I try to keep my own ferritin level at mid-range or a little bit higher, which would be about 160 mcg/L for your reference range. When it was low in range I could only get upstairs by crawling on hands and knees.
Mch (hbe) 27.3 pg . This is low. Range 28-34
MCH - Mean Corpuscular Haemoglobin - May be low in iron deficiency, inflammatory conditions and thalassaemia, according to the first link I gave.
MCV 82.9 fl. Range 80-100
Yours is low in range. MCV - Mean Corpuscular Volume - decreased with iron deficiency, longstanding inflammatory disorders and thalassaemia
Cholesterol 220 mg/dl. This is high. Range <200 normal and >200 high.
Cholesterol rises in people who are hypothyroid and not on treatment or are under-treated. Having said that your cholesterol looks perfectly healthy to me. You might like to read this post from a blog by Dr Malcolm Kendrick. (Your cholesterol is 220 mg/dL. This is equivalent to 5.7 mmol/L. Check out the graphs showing mortality risks. They reduce the higher the cholesterol is.)
Vitamin b12 148 ng/l . Low. Ränge 180-914
This is outrageously low. You need to be tested for Pernicious Anaemia. And you need injections to get your levels up. For advice on what to do, join the Pernicious Anaemia Society community on HealthUnlocked here - make sure you tell them that you are in Germany because it may alter their advice on what to do, and it may suggest alternative forms of treatment :
Click on the above link and then click on Follow in the banner.
What strength of B12 pills have you been given? And what are the B12 tablets made of? There are 4 different kinds of B12, and some are better than others in certain circumstances.
TSH is 2.62 mU/l . Range 0.35-3.5
If you have been diagnosed hypothyroid then your TSH is too high and you are under-medicated. Most of us feel at our best when TSH is 1 or under. You also need to know your Free T4 and Free T3 levels, and also your levels of thyroid antibodies. If you don't have enough information about yourself, getting well is less likely.
I would say, in summary, :
You probably need iron supplements.
You need B12 injections.
If you are being treated for hypothyroidism, then you need an increase in dose.
You need to get serum iron tested before supplementing iron, just as an added reassurance that it is the right thing to suggest. There are some uncommon people who have low ferritin and high serum iron. If they supplement they can feel awful because the serum iron rises but their ferritin doesn't. (I'm saying this about iron also because you aren't anaemic, which surprises me under the circumstances, so I'm wondering if your serum iron is surprisingly good, and we just don't know about it.)
You need to have folate tested.
You also need to have vitamin D tested.
You also shouldn't be taking just a single B vitamin, you need a good quality B Complex. People feel best when they keep all their B vitamin levels in sync i.e. supplementing one and ignoring the rest isn't a good idea. They should all be supplemented together.